I have a 2005 6500 Trek mountain bike and I have been rideing it for about a year now. I mostly ride in gears 4-8 and the teeth have worn down on the rear Cassette to the point of needing replacement. The bike came with CASSETTESRAM 850 11-32, 8 speed. I am thinking about the dishing out the cash and getting Shimano XT cassette. If I get a higher quality cassette like the Shimano XT will the teeth last longer or will I just get better performance without the teeth lasting longer?