Pros
The absolute best reason to work at MaPS is the people. I don't know how, but their hiring and recruiting practices seem to attract some fantastic people that I know will be lifelong friends. It's a great first job in that they pay decently, there's lots of other young people, and they are a relatively intelligent, interesting group of people. It's a "real" company and they actually do act professionally, unlike a lot of smaller companies.
Cons
Do not work at this place if you want to be creative. If you're in the lower ranks, you'll spend most of your day doing mind-numbingly tedious tasks like checking numbers and reading outputs of stats files. Fun, right? Only if you are an extremely anal, detail oriented, and quite frankly, boring person. That said, no one at the company really likes doing this type of work, and since most of the people there have degrees from really good colleges and grad schools, it's mostly insulting for everyone to do this type of work. Maybe they should consider hiring temps to do number checking?! Either way, you won't really get to use your brain until you are a project manager/associate or higher. But, by the time you rise to those ranks, you may not want the job anymore. There were a few folks who sneaked up to the top through sheer ability to navigate the politics of a very tightly-knit group of partners, either by marrying their friends or playing lots of golf with them. (The people who moved up, rather than out, were never the really nice folks). Other than that, if you are even remotely an "individual" of any sort, you will stick out here like a sore thumb. Everyone dresses in very conservative Boston attire (not suits, but the same J.Crew outfits), and while everyone is super nice, innovative ideas are NOT welcome here. Most people stay for about 1-2 years and go on to bigger and better things.