If you actually start trying some singletrack you will likely get a better workout and than road riding. For me the road is not about hammering, I look around and enjoy the sites. Mountain biking engages the whole body and I find I burn as many calories on a one hour moutain ride as a two hour road ride. I am also sore in different places. I like the compliment of mountain with the road.

Congrats on the find, my hardtail Tess is a Craigslist steal. Other than the scratches on the frame it was like new and less than 1/3 the retail for the bike. We are good buddies now. By the way, I name all my bikes so we can talk like old friends.