Both watching vids and vidding are nearly exclusively done with headphones for me. Especially vidding, because otherwise I think my flatmates would actually murder me.

I don't watch vids with speakers or television hugely often, but when I do, I find it's the TV experience that's different. And I do think you lose a lot of subtlety with the TV, just because there's usually more going on than simply you, your screen and the vid.