Originally Posted by seely

If you're having to "tweak" your derailleur as often as you say, I hate to say it but you aren't doing something right, or the thing is completely worn out. Are your jockey pullies worn? Do you keep the chain lubed and clean? Is your derailleur hanger bent? My XTR rear is about 3 years old now, and has been on two different bikes with the mileage around 3000mi probably. In that time its been slammed into the concrete when I cased a 5' stair jump, and run through mud, water, sand, and neglected at times. I've never had to adjust the limits (except when I bent a hanger & need to limp home or switched btwn. bikes)... just tweak the cable tension a couple of times, but once the cables are stretched I maybe need to give the barrel 1/4 turn every couple of months and thats about it. Same went for my LX derailleur, and my Ultegra 600 (OLD Ultegra). I would carefully evaluate your drivetrain's condition and cleanliness and then decide if its really the derailleurs fault.