I own both consoles and I will likely buy the 360 version for the following reasons:
1) High quality 1080i upscaling. 720p does not look good on my 1080i native TV. The PS3 version *may* support high quality upscaling through software, but many PS3 games only support low quality upscaling, while others don't support upscaling at all.
2) Rumble support. Again this *may* be supported by the PS3 version, but then again it may not.
3) No sixaxis nonsense.
4) The 360 version will likely look/perform a little better. PC based cross-platform titles always do, and I see no reason why this game would be any different.
Though I may reconsider if I have to swap discs while backtracking, like in Star Ocean 4.