This past weekend I installed a pitch stop that I purchased from this gentleman here:
http://www.ixizconcept.com/
This is one seriously nice piece. I am very impressed with the quality and solidness of this pitch stop. Before I installed it my motor was all over the place, rocking this way and that. After the install the motor just sits still and purrs. Shifts also feel more solid since the motor doesn't rock as much. I got the race version but there are 3 different versions: Race Competition and Street
With mine there is an increase in the NVH associated with the motor. Nothing that dramatic you can just pick up certain sounds better with the stiffer bushings and solid bar. I am still waiting on the pics that I took during the install, but here is another from the manufacturer of the prototype:
I will update this with some more pics once I get them off a friend's camera.