I spent several weeks here and had a great experience.
Frontdesk: Everybody was very nice and very helpful - maybe the best frontdesk I've ever encountered and it's hard to be flawless for several weeks.
Rooms: I got the one without the walls (it's like a loft). It's great. You get a big refrigerator, microwave, oven, two tables (one for work and one for the kitchen - both have outlets so you can work wherever you want) and a sink.
It was very well designed and I actually felt it had more space than I needed.
Extra Services: The cool thing is that they shop for you. You write what you want from the supermarket and they bring it to your room during the day. In Cambridge you can also get almost anything online, but that was certainly handy. They also accept pets - this never bothered me.
Breakfast: It's a standard hotel breakfast. It's not outstanding, but you have bagels, donuts, eggs, cereal, waffles; lots of choices. You can also take plastic plates or cups to your room.
If you prefer Marriott's breakfast, you can just walk a block and eat there (not for free).
Stuff to buy: The frontdesk has an assortment of quick foods to buy. Instant noodles, chips, ice cream, power bars and what not - it helps a lot.
Room service: ATTENTION. No room service, You may order from many restaurants nearby and they bring the food to your room, so it's almost the same thing. But if you realy need room service, you may not like it.
Location: Great location. Starbucks fans have 2 stores withing 2 blocks (one is right beside the hotel). MiT and the Coop store (with study supplies, restaurants, haircuts, books, magazines, etc..) is very close. The subway is also very close and with the subway (or even by foot) you can go around most of Cambridge and Boston very quickly.
Wireless Internet: I was a little worried about that, but I had a great experience. It worked well for the entire stay. There is a minor annoyance in which you have to login again every day to make it work, but that's a standard in most hotels and it takes about 10 seconds.
I spent several weeks there and found a couple minor issues. Still, I think they deserve the 5 stars (if I become too nitpicky I'll never 5 star anybody):
Housekeeping: Twice they entered the room very quickly without much of a warning (once they tried to zap through the door and once they knocked for 1 second and then came in - both times they got stopped by that little chain, but pretty much ignored the Do Not Disturb sign). That happened to me in other hotels before. Since I spent most of the time in my room working or studying I figured this is something that happens. I'm not gonna break my 5 stars, but this may be a deal breaker for some.
Gym: It was a small nice gym, but one of the "exercises" in the main machine was broken and they didn't seem to have that figured out.
If you require a more hardcore gym, you have options close by.
Even with some minor issuances, I was very pleased with the hotel. I would definitely stay there again. I think it is good for any category, but especially helpful for business travellers and students.
PS: I didn't use their computers or printer services, so I can't comment on that.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.