I the have shadow 6 and is a great controller, I mainly play on 360 and I've modded my d-pad and after the mod, is the best pad so far, maybe followed by the Shadow 6...
I've tried many controllers for ps3 cause I'm so used to 360 layout, and had been having troubles with diagonals in standar ps3 controller, so far the most precise d-pad is the SF controller one that came out for ps2, the d-pad is so good, as well as the buttons, the only weird thing is to have 6 face buttons.
The shadow 6 has some troubles with the buttons, I had to change the first one cause you had to press really hard the x button, and the second one that I got has a similar problem with the triangle, but is tolerable.
I was about to buy the rocket fish, but I read some bad reviews about the d-pad getting stucked.
Being a player with a lot of execution I have so many toughts about the controllers, like I can get a lot stuff on a standard ps3 controller that I cannot get on standar 360 and vice versa, this sucks, I wish I could build my own controller.