When I bought a PS3 we had 2 controllers, 1 came with the PS3 and one I bought separately (Sony product).
My brother plays with the controller that came with the PS3 and I play with the controller bought separately.
Now, when I play Black Ops in Multiplayer, you need good aiming, my controller's analogs are so stiff or over-sensitive that when I press left,right,up or down, it just overdoes it so I end up not hitting anyone.
But when I play with the controller that came with the PS3, the analogs are so smooth and I used the same sensitivity in Black Ops and I can aim better.
My stiff controller is now broken so I bought a new one which was also made by Sony, but it is also stiff.
My questions are, How can I fix the stiffness or How can I determine which controllers are stiff and which controllers are smooth.
I use my controller as much as my brother uses his.

Is your brother's controller used significantly more then yours? (not a lil more, ALOT more.) if his is worn out it may be 'smoother' Or does he use it rougher? Hit the joysticks alot? That could be the issue.

My brother's controller also has nice smooth joysticks but the buttons have almost no resistance. This is due to his being 3 years old and being used about 6 hours a day every single day. (Mines 1 yr old, about 6 times less used then his every day)