If nothing else, you can be amused at my naivety again.
For the most part (say 90 per cent of the time) I watch vids on my laptop, curled up on the sofa, with my headphones on. The viewing feels very intimate. If I download them I take the time to watch them multiple times, and I do that with any vid I'm serious about watching (which is quite a lot of vids). I don't move on to another vid unless I feel I've fully digested that one.
When I'm browsing for new vidders or vids I do use YouTube (or the Ning network to a lesser extent). This wasn't possible on a practical level for me until recently because broadband is so slow here, but I am now able to get decent streaming for the most part. However I'm far more brutal on streaming sites--if a vid doesn't grab me or hold my attention I'll click on pretty damn fast. If there isn't something extra about the vid (interesting subject choice or song, a fandom I like, a vidder I like, a style I'm curious about) I won't put in the extra time. Whereas with the vids I download I tend to give a vid time to grow on me--even if I don't like it straight up I rewatch and see what more I can get out of it.
So I have kind of two extremes--one the uber-attentive, intimate viewing--the other the fast 'entertain me or else' low attention span kind. ;)
Either way, the vids are small in size on my screen. It was only just before Vividcon (and too late for my premiere) that I worked out how to hook them up to my TV so I could see them on a slightly larger screen. That blew me away, so I had a teenie foretaste of what was to come.
The first thing I wrote was focus. The Vividcon audience is extremely attentive and anticipatory. You can feel people expecting the vid to entertain them. They're there because they love vids and are open to them so in that regard it is a very positive audience. This definitely tallied up for me with my own feeling of focus at home, except that it felt very peculiar to have tens of other people craning over my shoulder with me. ;)
Laughter was one of the first big things I noticed--it's a great feeling to share laughter with a crowd, but the laughing itself takes time, so the vid viewing gets a little interrupted. Depending on the pace of the vid this was either no problem at all or a little tricky, especially when parts of the crowd laughed at different times than me. It felt like I was either riding with the crowd and the vid (and getting a huge high off that) or feeling slightly out of snych emotionally. For vids where I didn't quite feel in synch with the crowd, I can't say it made me think less of the vid--it's more that it made me reflect on why the vid wasn't making me laugh at the same times (e.g. missing fandom in-jokes or possibly just having a different sense of humour). It taught me more about myself as a viewer so it wasn't a bad experience--just a different one.
The obvious is more bearable. I wrote this sentence and I hope it doesn't prove offensive to anyone, but I found that really obvious lyric and image combinations 'popped' better at the con than they would have to me at home, in part because the audience was so open and receptive and predisposed to like the vid. Of course these things are subjective--one person's subtle is another person's obvious and vice versa. But in general I think when you're watching a vid only once and are possibly distracted by all the people around you or have slightly obscured vision, the slightly more obvious choices can really work at keeping you following a vid's trajectory.
Related to that point is the fact that you live in the moment as the viewer. Everything is before your eyes so fleetingly that even just seeing a character, fandom, ship or canon moment you like can be a 'high point' of the vid. There were plenty of instances throughout the con where people reacted simply to an image (bradcpu's observation that people seem to laugh if you just show them a shot of Spock being my favourite illustrative example! SO TRUE, omg, what is that about?! I even found myself doing it by the end! But I would never have done this at home.). So again, I found this lead to a more forgiving viewing experience as long as you were showing something popular that lots of people would get a kick out of.
This also meant that the one-concept vid is more enjoyable. By a one-concept vid I mean a vid with one very clear point that is made over and over. For instance, it could be a comedy vid, such as one based on the idea 'Ten makes a lot of stupid facial expressions' (fictional example) that then proceeds to show this to an amusing track. Or it could be a serious meta vid that says 'this ship is really fucked up' and proceeds to prove its point. At home, I've got to say that unless I find the thing being said to be fresh and new or something I'm personally very attached to and want said by the universe, I have limited interest in such vids. The main reason being that once I've seen them once I feel like they don't hold up to multiple viewings. I keep digging around for more and finding that no, no, they just keep on saying that one thing. They may of course say it very well, so this is my own little prejudice here as a home viewer. At the con? These go down REALLY WELL--to me too it turns out!--I think because the audience really has a chance to 'get' the vid, even when played consecutively amid tens of other vids. It's gratifying to the viewer, especially at the end of a long day of trying to parse a multiplicity of complex and diverse vids quickly.
This leads well to the next point, which is that watching so many vids consecutively--having to change pace, emotion, fandom, viewpoint, mood and level of intellectual engagement every three to four minutes--leads to vid fatigue. Everyone talked about this at the con and a lot of people were pacing themselves with vid shows to avoid it. There is a certain point where if you fully enter into every vid and really connect with it as much as possible you get overloaded. One of the unexpected benefits for me of experiencing this is that it broke down some of my own prejudices as a viewer, and it lead to me slipping into different ways of watching a vid. For instance, I found that at some (very fatigue-driven times) I was watching a vid mainly at an aesthetic level--for pure beauty, for motion, or for colour. My conscious mind kind of tuned out at these times but I still greatly enjoyed the vids and for the most part still felt an emotional power drawing me through. That's a really different experience for me because I over-intellectualise everything, and even my way of being squeeful about something usually involves thinking about it obsessively, writing arguments in my head, and so on. So I found this breakthrough to be really powerful and I think really healthy. It made me appreciate other people's vids on a new level, understand a little about how other people view vids and also be a less critical viewer.
Another thing which happened was that watching vids back to back allowed for greater capacity to see parallels between them or to draw links across and between vids. This could itself enhance the viewing experience. A great example was how one person in vid review commented that watching heresluck's ensemble Friday Night Lights vid prepared them well (as a non-FNL viewer) for w_a_prince's Becoming Brothers, which focuses more tightly on two characters of the cast. At first, it felt really weird to me to be relating vids to one another, because the connections were so arbitrary and I would never have made them at home, where I really consciously separate each vid out in my mind. However, themed vid shows by their nature invite reflection on the similarities and differences between vids, so this process was both legitimate and rewarding--especially in conversation post-show. It also built, for me at least, a greater sense of community: as if by talking about how vids related to one another we were building a web of connectedness between each other. Given that a lot of vidders at the con are inspired by other vidders at the con, this is probably not surprising--but it was something which until I experienced it in person I wouldn't have been drawn to do at home.
On a physical level viewing a vid on a bigger screen for the most part meant I could take more in visually in a shorter amount of time. However this decreased rapidly as soon as my vision was impaired at all, which it naturally was in some sessions. At home I'd be a control freak about this, not wanting any vid to be biased by me being distracted. Being at the con helped me loosen up about that. But when I could see properly, motion took on a whole other level of importance. First, I noticed I had a greater tolerance for amount of internal motion in a shot, but conversely (and I've know idea why this is so) also greater tolerance for long slow shots that allowed some resting time. Second, I noticed interrupted or jerky motion far more (perhaps because we're used to seeing polished editing on bigger screens? I don't know), and that helped me understand why some vidders put so much importance on this, especially in a context which doesn't allow as great a capacity for private intellectual engagement. For while I could take in more visually I found it harder to focus my mind, especially as vid fatigue kicked in.
Still, some of the most exciting vids at the con for me were that ones that I can't wait to watch again and again at home. I can't honestly say I grasped them in their entirety at the con. As I suspected, I'm not able to read that deeply on as many levels as I would like in one viewing. But having that first intriguing viewing 'live', being left thinking 'what the hell was that?' or 'was that vid really saying ...?' or getting heaps of sparky intra-fandom meta thoughts from a vid that I desperately want to explore further on re-viewing was very exciting. And it was kind of a great game to see how much you could get out of each vid on one view. Even if it was a pretty tiring game by the end. :p
I had worried that watching at a con would mean a less emotional experience for me. That proved both true and untrue. There was a degree to which it was hard work shifting emotion with each vid. Whereas at home I'd find it a failure of the vid to make me sad (if that was its intent and it didn't), at the con I was sometimes aware that this was less to do with the vid and more to do with me still being peppy from the previous one. However, that said, truly powerful vids that had great personal resonance for me blasted through that completely and felt all the most exciting for that reason. I was very impressed with the VJing overall--great thought was put into controlling the emotional trajectory of shows, and I really appreciated that as a viewer. Naturally there were some spots where for personal reasons I either found it hard to move on emotionally from a vid or hard to enter a vid emotionally. But luckily since most vids are available online I can always give them a second chance, and I look forward to building a new relationship with them at home now as well.
Summary: I didn't feel like viewing at the con invalidated the choices I make at home as a viewer; I feel it expanded my possibilities and freed me up in a positive way, as well as teaching me more about myself and others as viewers.