Hi, I am looking to buy a quality used Mountain Bike. I am 5'10, 180 lbs. The bike would be used for tight woods trails through some moderate hills. I am hoping to buy a used bike , about two or so years old, and am thinking that I might get a good deal on one without disc brakes, as it appears to be the "Must HAve" item on the new bikes I see in the store. Anyone have some favorites in terms of quality/performance and bang for the buck? I was oogling a Specialised Stumpjumper new in the store, and it certainly appears to be a quality piece, but I am more familiar with cars and motorcycles in terms of evaluating component quality or seeing under the paint job. Opinions greatly appreciated.