I prefer the PS3 controller. Though the 360 pad is more ergonomic (if a little clunky and heavy). The triggers are better on the 360 pad, everything else is better on the DS3. DS3 + Real triggers = perfect pad.
One thing I've always liked about the DS3 over the 360 pad is that the sticks are looser and have double the diameter of movement, (1cm vs the 360's 0.5cm) which basically gives you double the range of movement finesse. Which is why racing games are so much better (imo) on the DS3. I also like that the analogue sticks are together, and that the face buttons are analogue (pressure sensitive) (360's are not). Perfect for games like GT5P.
One thing I've always liked about the DS3 over the 360 pad is that the sticks are looser and have double the diameter of movement, (1cm vs the 360's 0.5cm) which basically gives you double the range of movement finesse. Which is why racing games are so much better (imo) on the DS3. I also like that the analogue sticks are together, and that the face buttons are analogue (pressure sensitive) (360's are not). Perfect for games like GT5P.