Hi,
I used to ride a mountain bike, but had back problems with it and switched to an HP Velotechnik Grasshopper. This spring I have established the habit of commuting 10 miles each way to work on a very convenient bike path and it hardly takes longer than driving in the traffic. The comfort level is like out of a dream, I go faster with less effort, and enjoy riding more, and feel better after the ride on the recumbent. Its quite blissful, being out in the world, watching it whiz by, hearing snippets of conversation, being relaxed, and exerting oneself can be one of the best parts of the day. I ride more often and further than before with no bad side effects. The bike is in fact the most comfortable thing I sit on each day. Many people are curious about the bike so its a very different and positive social experience as well. I think many people could benefit from switching to recumbent, its a healthier, more fun and more effective mode of transporation. I do however, hesitate to ride in dense urban traffic because the bike I have is a bit on the low side, but with practice I may feel differently. Commuting by bike also saves measurably on gas and reduces car dependency. Go 4 it and good luck,

- Andrew