I live in Worcester. In the past, I would almost always fly out of Manchester on Southwest. My friend lived in Nashua and it was about 15-20 minutes from the airport. I would park at his apartment and he'd drop me off.
But he has since moved into Manchester itself, and only has on-street parking. So for my next trip, because flights out of Logan were cheaper, I decided to try flying out of Boston. Other than a quick trip to my parents' for Christmas a few years ago on the now-defunct Independence Air, I couldn't even tell you the last time I flew through Logan.
The only problem with Logan is parking. Even if you take the Logan Express shuttle, you still pay to park at the shuttle's terminal. While cheaper than at the airport, it's still quite a bit. So, unless I find a friend that doesn't mind driving me to/from Logan, I'm planning on parking and taking the subway into the airport. Either at Alewife ont he Red Line, or at Woodland on the Green Line. Worked quite nicely when I flew that time on Independence. $4 a day to park, and then $1.70 each way subway fare. Can't really beat that.
(Plus, I've been wanting to try JetBlue for quite a while....)
-Rob