I've always loved this design.
When the "boomerang" concept was floated as a potential design for the PS3 controllers, I nearly cried.
Also, remember the DualShock 3 is rechargeable by default - no add-ons required. And its a lot lighter than the 360 controller...
Play Flower with it and it disappears - and the small motion touches in PS3 exclusives do much to differentiate it from the 360 pad...
I love both to tell the truth... I've loved the 360 controller since I first layed hands on it and the same with the DualShock 3... There really is some great parity between these two consoles. The Wii controller is great as well but thats a whole 'nother story..... :)
I also love that everything is wireless now by default!! (f u wired 360 controller - you're dead to me!!)
The D-Pad is hands down the best ever. 360's is horrid.