I started commuting by mtn bike, then moved on to a hybrid. Lately it's been my fixed exclusively (at least for the last 3 weeks or so). I like how light and simple it is. Also, I like climbing the hills with a long gear because it's a lot quicker. If I were on my soho I would be down in 3rd gear taking all day to climb. The one thing I like least about it is I have to set up for a fart. With a freewheel I can just lift, coast, and push anytime. It's a real drag.