Pros
Small tightly-knit teams allow for constructive teamwork while giving real ownership of the work that you do. Generally open to feedback and improvement both on personal and corporate levels. Casual and friendly atmosphere. Overall lots of nice people to work with. Beautiful office and though far from Cambridge centre, still very commutable. Decent benefits package.
Cons
There's a clear lack of ambition. Lots of great people coming up with great ideas, and then there's a bureaucratic process by committee to deconstruct it and scale it back to the absolute minimum that they can get away with, sometimes to a point where the implementation doesn't even make any sense anymore. A second roll of red tape is then kept for later to wonder why consumers prefer competitor's products that look nicer, work better, have more features and cost less. A fair amount of petty office politics and egos to deal with, but I suppose some of that will exist anywhere.