Not a commuter, but I use 32c Panaracer Ribmos on my Salsa Casseroll for over 3 years and thousands of miles. While I cannot say I have been flat free, the flats have been few and far between, and at least in the most recent two, the fault was not in the tire at all, but in some rim tape that moved exposing the sharp edges of a couple of spoke holes. My usual routes take me over lots of broken pavement, gravel and some rough railroad crossings. The 32c Ribmo takes it all in stride. Funny thing is when I bought the bike, I originally planned to go with 35c Ribmos, but the mechanic made a mistake and mounted the 32c tires instead. After a quick test ride, I decided I liked the ride of the 32s and decided to keep them. That was over 3 years ago. I have occasionally thought of going down a size but I like the ride quality of the 32.