I decided to get a 2010 Rockhopper Expert 29er. There were a couple of upgrades I had done before I even brought it out of the shop. First, the stock fork, a Dart 3, was replaced with a much better Reba. The Reba SL I got is a lot higher quality air fork. I also replaced the stock x-5 shifters with better x-7 shifters. The biggest difference is the 29 inch wheels though. The largers wheels have a larger contact patch, giving better traction, roll over obstacles better, and once you are moving you roll longer with more momentum.