Certainly one of the most devisive controller designs, but the lack of two thumbsticks is precisely what I like about it. The pad centers one thumbstick and the trigger on opposite sides of the "main hull", with the rest of the inputs divided along two (remappable) zones, i. e. the outriggers. I have never held a controller in my hand with better ergonomics and holding adaptability. Even the size is just right for my hands.
It's the only pad that ever made FPS games on a console a joy to play for me; put in two analog sticks and you fuck with that formula. Its only serious weaknesses are the cheap plastic, especially for the thumbstick, and the weight (too light). Make a full metal version out of it, with some thumbstick material mods known from the PvP fighting game community, and it's the best. Well, at least for me.