I live in Marlborough and it's great! :) I don't have any issues with security and the town has a few things to offer. There are many shops and restaurants, it's an hour or less from Providence, Portsmouth, Boston and Worcester (all great hot spots), parks and they keep it clean.
I know the Design Pak Lofts - I saw the building go through it's renovation. I don't have any solid numbers on the utilities but heat does rise so anything above the first floor will be cheaper to rent. The building management should have that information. I can contact them if you like since IL is a bit far away!