Man, I miss having a subwayish commute. I think I'd gladly double the time length of my commute if it was walking plus riding (w/ time for reading) rather than just driving.
Yeah, I love my daily commute. 10-15 minutes of walking each way, some waiting for the bus, and some reading time on the bus. Better for the environment, for traffic, and for my sanity.
Well. . .the traffic is still hell in the Chicago area. 20 min to get to the airport on the L compared to an hour in traffic. . .and that's only to Midway.
As for the sense of community and such, I don't know. . .sometimes I like to relax on the train. In general, though, the L is great. . .comes often, moves generally quickly, etc. etc.
But yeah, displacing people onto the L for transportation as compared to driving, even though the traffic still sucks, probably helps the environment somewhat, too.