I like the 6500, actually have put 500 miles or so road biking it, with street tires of course
I have an 2006 6500.
Unfortunately after a recent trip it became damaged during shipping, so I replaced it with a Cannondale F5, personally I like the F5 ride much much better (off road, haven't put the street tires on it for riding the road). It fits me better, plus the sram rear derailer just shifts instantly compared to the shimano counterparts on the trek. Overall, besides going through the hassle of the shipping claim for the 6500, I'm glad I got a second chance at another bike.
HOWEVER, if you're gonna do alot of road riding, that lockout on the 6500 was very nice to have! My 6500 is still ride-able, I'm replacing the damaged rear-wheel, and the only other real damage is the rear triangles are pinched in by about a 1/4". If you're looking for a 21" frame I'll give you a heck of a deal!