Good to see you're moderator of this section! I think you'll do great!
Now, regarding your question:
First of all, I have a *VERY* low connection, so bigger or even bigger, it doesn't make any diference
Second, I'd vote for the large screen. Makes it look more cinema-like. But this doesn't mean I would enjoy less a video in a smaller screen!
AnnaBtG.
P.S.: LOL at Yvonne's last comment