I put a new 2008 Specialized Sirrus Pro into service last year as a commuter bike. I ride to 36 mi RT work 3-4 days a week and really enjoy it. The commute is almost all on paved roads - a couple of miles of paved MUP and about 1/4 mile of gravel shoulder. I am 6'4" and weight about 250 lbs.
After about 1000 miles I took the bike into the LBS for a general tune up. Although I hadn't noticed it myself they spotted and showed me where the metal on the back rim was actually cracking around near the spoke holes. The great news is that Specialized immediately replaced the wheels with some upgraded ones that are stronger. I now have about 2200 miles on the bike. I'm using Specialized Armadillo 700 x 28 tires (they are awesome).
Yesterday I had one of the spokes on the rear wheel break, and the wheel went a bit out of true - bad enough that I had to loosen the rear brake cable to stop it from dragging. I dropped the bike off at the LBS on the way home and as always they will repair and adjust the bike.
My question - does anyone have specific wheel recommendations for a heavily loaded high use commuter bike? I have really come to enjoy the commute and its personal benefits and am willing to spend a little to upgrade to a stronger wheel if it will improve reliability and dependability.
Thanks in advance for any feedback you have.