One quick suggestion: When I change an option in the option menu (specifically, "Mute all Players"), I shouldn't have to change that option everytime I play. The options menu choices should save each time I make a change and be the same every subsquent time I play.
Uncharted 2 & 3 had the same issue, I offered them the same suggestion - but it was ignored. So I'm really hoping it's not a "Sony" issue (whether a hardware/software limitation for whatever reason, or a Sony policy that prohibits saving "options" settings).
There's only a few things more annoying then having to retweak my options preferences everytime I play.