Pros
Learned a lot while I was there and had some great mentors. Lots of smart engineers to bounce ideas off and collaboration was good.
Cons
If you're not part of the clique, you have little hope of making it there. There is one department that seems to rule the office in North Andover and if you aren't on good terms with the director of that department, you'll be on the list. This particular person keeps track of all comings and goings and has spreadsheets of when people come in, go to lunch, leave, etc. If you're not on their good side, they will complain to their upper management until you are put on a "performance improvement plan", which is really just waiting it out until they can fire you. I felt like I lost some of my integrity while working there just in an attempt to fit in and ensure that I wouldn't be fired.