I have run Xt for several seasons of racing and XTR for the last 2. The difference is very minor but it is there. It only becomes apparent in really rough conditions such as one sees on a hardcore xc track. In addition it has real oilite and bronze bushings, to increase the service life.
RapidRise is a matter of debate. I preferred Suntour's reverse front der. The rapid rise design is supposed to be superior in action, but it requires a fair bit of getting used to, and I like being able to pull the cable to downshift when muddy.
On another note:
Syd, when I refer to the construction of these, look for yourself. Can you possibly tell me an Acera uses bushings? It uses the aluminum body, which can be bent by hand.
When I say these are reverse compatible, that is not a RR reference. It is a term we mechanics use to note a part can be used in lesser or older systems.
