I like SS because of the challenge. You have to spin fast, grunt out the climbs and learn to conserve momentum. Riding around town on my geared commuter, I found I was using 2 gears out of 24. I figured that I could get away with one gear, and I did. I also ride a rigid SS mtn bike for short off-road sessions, and it has improved my geared/suspended riding significantly. Everyone I know rides a FS mtn bike, so it's a real challenge to keep up.

Oh, and when I'm riding home from the pub, gears are the last thing I want to worry about...