If you're a die hard xbox 360 controller fan, then you should really look into Mao's post about the face lift.
This is a random review of the actual controller, not the face lift, but he covers the Dpad which is the only difference...
If you aren't concerned about the analog sticks not functioning, I can convert the ps3 pad to work on 360. I would be able to keep both systems (still minus analog sticks on both systems) if I had a source of Paewang pcbs.
There is also the option of installing a cerberus and a 360 te pcb inside the pad, but that's a shit ton of work. It would give you ps3 and 360 support and still have working analog sticks on ps3 side.