I commute 35miles round trip, more than half of it in open country roads exposed to lots of wind, and other portion, on city streets with railroad crossings.

I've been doing it on a 199x rigid mtn bike with slicks. Weighs in at about 40lbs loaded for my typical day. It's not an ideal bike, but it's what I had. I also have a Bianchi road bike, but don't want to abuse the tires and wheels on the rough streets and rr crossings, but it would be much faster.

I've come to the conclusion that would I would like for a commuter is something with 700c wheels, (roll easier), 700x35 tires (handle rough pavement better), disk brakes (better in wet, and less maintenance than rim brakes), and I think a flat bar with bar ends, (maybe not quite as aero as drops, but more maneuverable in traffic and comfortable... also cheaper shifters and levers). Also needs to have rack mounts.