I have a Minoura B60R. I wanted the Kurt Kinetic, but being a poor student, that's a little out of my price range! The Minoura's magnetic, so it's noisier, though not terribly so. It's lightweight, folds for storage, and while you will need to change skewers, it's not all that difficult to get the bike in and out.

Rollers are a better workout and you can improve your handling skills, but I'm pretty sure I'd kill myself with them...