I got hit by a cold/sore throat a couple nights ago so even though the weather's great, I decided on a partial commute. While driving to where I park my car I saw plenty of traffic and decided "eh, whatever" and parked the car further out, and rode most of the way in anyway.
It was a bit more tiring than usual, although that's possibly because I always get the urge to keep up with the roadies on the MUP. I am gonna switch out my 26x1.95 XC knobby tonight though for a 26x1.25 slick. Should make a difference. It's funny because when I first got my road bike I thought "there's no way I'm going back to a MTB for commuting". Now that I've done a century on my road bike, the commute distance is so short that I almost prefer the MTB for the extra workout.