Completely updated now, I only request if you change systems to please create a new post.
@sameoldstuff: Thanks, I'll update the OP with that PSN ID
I've heard about the lag problems but Atlus has stated that they are working on it. Apparently BlazBlue (same dev) had horrid lag the first week and after the patch was silky smooth.
I think the high purchase rate for PS3 is due to a number of things already mentioned. Dpad is playable on PS3 and horse crap on 360, not everyone has a stick. Persona/SMT games were Sony console exclusives. PS3 is the leading console for fighting games anyway and the anime reason as well.
I normally play all my fighters on 360 since that's the fightstick that I had, but picking up that deal for a PS3 one today made me switch for this game specifically. 360 owners shouldn't fret, it will be fun regardless.
Changing my set up to PS3. The majority of people seem to be playing on there (not just here) and I found a brand new MadCatz TE Round 2 for PS3 for 50 bucks at a yard sale today. Can't make that shit up.