So after beating Arkham Asylum on 360, I played the PS3 version of Arkham Asylum to see what the Joker levels are like. Pretty much the same as the Batman Challenge Mode levels, except you're fighting the "good guys" as Joker. If you ask me, PS3 doesn't have a huge advantage. A nice add-on but nothing special.
One thing I notice though is that 360's graphics are slightly better. And this surprises me because the PS3 is the more powerful system. But I've read that developers find it harder to tap in to the PS3's full potential, while the 360 is much easier to work with. It's not readily noticeable, I mean both games have dope graphics. But if you're trying to spot the differences, you'll notice that 360 graphics tend to have better lighting, more vibrant color ranges, and smoother graphics. PS3 graphics are sharper, but also slightly more pixelated. And the lighting isn't as good. Another thing I don't understand is why PS3 games only go up to 720p, and no games up to 1080p like the 360.
/endnerdrant