I ride in a uni club.
It's both MTB and Road.
I like it- I've always ridden with "just mates" in the past but having a whole club, even a small one like ours, behind you means there's always someone to ride with but it also introduces ar eally excellent social scene to the riding, and as such some of my uni club mates are the best friends I've ever had.
It's brilliant for new riders- using the experience of old hands that they'd not normally be able to get. It gives you proper back up at races as there's always people drafted in, and we're looking at organising races and events next year which I think'll be a laugh.
Contrary to popular belief, once you get off the internet most people insist they're shite riders (myself included, even if I do come of as being god's gift on here) and will surprise you.
As for the road/mtb thing- it does mean we can switch between disciplines easily, but the two don't mix. Trips are harder to organise and the only real gelling is a social things, but due to the size of the cycling scene where we are we can't have 2 seperate clubs.