I also think it's an outrage to keep that same basic design for over 10 years, I honestly could not believe my eyes when I saw it announced. Why can't Sony release another controller as peripheral, so that we who like asymmetrical thumbstick position and usable triggers can have nice gaming experiences with that machine?!... No need to do anything about d-pad though.
I think the sixaxis is more than good enough. The only thing I like better on the 360 controller is the bigger triggers - they are more precise, and less prone to accidental pressing when putting the controller down. The analog sticks also seem slightly better for FPS, but it's a minor differnece. Otherwise, the DS3 is more than good enough for me.
A big plus for the DS3 for me is the symmetrical design. It doesn't favor left or right handed and it just works well. I'm sure that for certain types of hands other controllers could be better, but that's for third parties to solve. Also, all the buttons on the sixaxis are analog (as they were on the DS2). That's a big plus imho, even though it isn't always used (I wish it was used more often) - if you play a game like GT, you can actually play it with x and square for accellerate and brake quite well because of it - experienced players do both with just one thumb, sometimes at the same time.
Also, let's not forget that Sony designed the boomerang controller for the PS3 initially, but they reverted to the DS3 design by popular (press and others who tried it) demand, though in retrospect had people known about the motion controls they might have changed their minds.
And of course I've been a proponent of the motion controls a looooooooooooong time already.