In reply to your question Shadowblind, from a track building process there was no difference.
The assets in the levels (detail in the models, texture sizes and amount placed in the worlds) are the same on all formats. Both games shared a single asset database.
The code team lead on the 360 at the very start of the game until we had something up and running. From then on though, both platforms were developed in parallel. Some of the art team would use PS3 and some would use 360. The leads would then check everything was running ok on both platforms from a visual and performance point of view. You should find both games look and run the same.
I can’t really speak for the code team as I should think there was a great deal of difference for them to deal with!
It was great having them both being developed at the same time. When you demo the game to the press you could just say “what platform do you want to see?”