Hey Philly....
Sorry, I dont know anything about those specific depts., but I have some suggestions as to how you could find out...
I would recommend meeting with someone from each of those depts....and ask very pointed questions before you join. Some important ones include: Do aux officers have police powers? Can we carry? Can we ride along with regular officers?
What kind of training do they provide? Are aux. ever called to assist regular officers?
You want to go to a dept. where you get as much experience as possible...that said, pretty much every aux dept in Mass is limited in what it can do. Don't think you will be answering calls, 'cause you won't (unless all the regulars are busy, and the nature of the call is pretty minor).
I've been on two different aux depts...and that has been my experience. Maybe someone else will post a different one.
Still, you can get some great experience that will serve you well when it is time to look for that first job. Take it for what it is, and don't get frustrated when you can't do that much. It is still a very worthwhile line to have on your resume.
Good Luck!