At one point, I made a conscious trade-off to live in the city, even though I was working in the burbs, because it was closer to my friends and things to do (and I am a single man). I had a 30-35 minute per day commute through annoying Boston traffic but it was totally worth it.
As for the sweat issue, I have been cycle-commuting for well over a year and often it doesn't matter how slow I go, I will still sweat during most of the seasons around here. Genetically, I'm a moderate sweater. In the colder months, it's really hard to balance against biting cold and sweating. In the hot, humid months it just doesn't matter. After 5 minutes I'll be sweating, backpack or no. Luckily, I don't really care and am fine sitting at my desk in an undershirt while I cool off. I keep a change of clothes in my desk for meetings. Not everyone has that luxury, though.
I went through a phase of 9-mile cycle-commuting and there's absolutely no way I would have been able to show up without stopping by the gym to take a shower first. There is no pace slow enough that I would not sweat through at least one layer of clothes. Believe me, I tried.
Incidentally, being in shape or not has nothing to do with it. I've been active my whole life and have always sweat-- and know people who sweat much worse than me.