I wouldn't agree that the commuter rail is unreliable - in the 3 years that I used it twice a day, I can count on a single hand the number of times it was more than 15 minutes late. The later peak hour trains sometimes get caught up in congestion in the afternoon, but even then the delays aren't too bad.

Then again, I worked from home during heavy snow. If your job will require you to go in even in severe weather, it's probably worthwhile to find a place on the subway line. The subways are slow and dirty compared to the commuter rail, but frequency is a world apart.