pc sfiv problems are overstated. most people have A or B rated computers and match up with three to four bar connections, at least in the US. people with crappy connections and computers can't be helped, they need to upgrade their shit or go play ps3/360.
I'd say I'm as likely to run into a PS3 user who gives me problems as I do with PC.
360 probably is better, but that's partially because Capcom isn't very good at coding (you don't see that big a gap with other FGs this gen, with the possible exception of VF)