The Ultegra 10-Speed RD-6600 GS Long Cage rear derailleur has the same technology as the Short Cage version, but the distance between its pulleys is a bit greater in order to accomodate the needs of a triple drivetrain.
Weaknesses: bushing wore quickly leaving slop/play in derailleur- not conducive to good shifts
Bottom Line:
after 2 years of use, bushing wore, causing play . Took me a while to figure why inconsistent shifting since I did not think an Ultegra derailleur would wear in so short a time. I have had excellent experience with longevity of Ultegra- one rear derailleur has 25,000 miles and still worked fine
