I have been activily riding for several months now and am looking to upgrade my old bike. I am looking into either the 2012 3500 Trek or the 2012 3700 Trek (both are in my price range). I am just wandering what all of your opinions would be. It looks as though the differences are in the Frame, Front Suspension, Rear Derailleur, and the Brakeset. I guess I am just wandering if there is much in the differences to warrant spending a little bit more or a little bit less. I am partial to the 3700 but like I said earlier I am just looking for opinions if anyone has any.

2012 3700 Disc
Frame Alpha Silver Aluminum w/semi-integrated head tube, bi-oval down tube w/integrated gusset, rack & fender mounts, disc compatible dropouts, replaceable derailleur hanger
Front suspension SR Suntour XCT w/coil spring & preload, 100mm travel
Wheels Formula DC20 alloy front hub, DC25 alloy rear hub; Bontrager 550 36-hole rims w/brushed sidewalls
Tires Bontrager LT3, 26x2.0"
Shifters Shimano EF51, 7 speed
Front derailleur Shimano TX
Rear derailleur Shimano Altus M310
Crank Shimano TX M131, 42/34/24
Cassette SRAM PG-730 12-32, 7 speed
Pedals Wellgo nylon platform
Saddle Bontrager SSR
Seatpost Bontrager SSR, 31.6mm, 20mm offset
Handlebar Bontrager Riser, 25.4mm, 30mm rise
Stem Bontrager Forged, 25.4mm
Headset 1-1/8" threadless
Brakeset Tektro Novela mechanical disc brakes w/Shimano EF51 levers
Grips Bontrager SSR

2012 3500 Disc
Frame Alpha Silver Aluminum w/externally relieved head tube, bi-axial down tube, disc compatible dropouts, replaceable derailleur hanger
Front suspension SR Suntour XCT w/coil spring & preload, 80mm travel
Rear derailleur Shimano TX35
Brakeset HL 280 mechanical disc brakes w/Shimano EF51 levers