I'm posting in this forum rather than the road biking or recreational forum because I figured you all would have the experience with the mountain bikes to answer my question. Hope that's ok.
So, my wife and I are looking at some used bikes to start riding around the neighborhood on. We are in a very rural area, but most of the biking we do together will be on the road or paved trails. However, I am also interested in getting into riding some trails with some friends, which she has no interest in. I'm just wondering how a mountain bike will be for 10 - 25 mile rides on the road. I know it will be slower and probably less comfortable, but will it be a LOT slower and REALLY uncomfortable? We're trying not to spend a whole lot, so I've been looking at older bikes like Trek 800s that don't have any suspension and I also have my eye on a bianchi super ibex that has full suspension. Long first post, but I would really appreciate some of you expert advise! Thanks!