Alright guys, like in my other post, I've been looking at the '04 Specialized Hardrock Sport, or '04 Hardrock XC or the '04 Trek 4300 or '04 4100. I was wondering which you guys think is the best and what I should look at to differentiate one bike from another. Thanks so much for helping me out as i make my first real bike purchase (those walmart bikes never count).