I didn't know trek used some of the same frames on multiple models...interesting. I do really like the feel of this bike and I'm very comfortable/confident on it. The 4300 is light and solid. I was at my LBS to other day and they have a nice used Trek 8000. Its a really sweet bike but it seems like it weights twice as much as my 4300. I definitely don't want to add a bunch of weight to my ride.