Okay, so I won a Specialized Hardrock 2012 at a Sober Grad Night raffle. The bike ended up being an XL and since I'm only 5'10" is too big for me. I went to the place where the sponsors got it from and the owner said he would give me a Trek Marlin Gary Fisher 29er for only 150 more dollars ( I could probably work him down to 100 because he said he wants to get rid of his trek bikes). I could also give him the difference of a Hardrock Sport. What should I do? I can answer any questions you guys have for me, I've never owned a mountain bike, the only mountain biking I've down has been at Northstar. I will be using the bike next year at college (UCSC). All advice is good, Thanks!