Bought PES on the 360, and it really isn't a very good game compared to Fifa, shoddy looking graphics, and the gameplay seems to have lost it's a way a little.
I've played both demo's on the PS3.
IMHO Fifa 09, which I've bought, is miles ahead of PES 2009, but of course I've only played the demo version of PES, so the retail version might be a lot better.