Pros
Good name to have on your resume. Fun, intelligent people to work with, relaxed working environment
Cons
Very few opportunities for advancement/promotions, while on the surface it seems to be the case that there are many. Forrester is a highly political place (even though this is only typical of a much larger company) - you can only win if you know the game and play by the rules. There is an unbelievable amount of red-tape to jump through in order to accomplish the smallest task (at the expense of productivity and quality), and employees are encouraged to invent more "processes" in order to receive praise/promotions, which is extremely counterproductive. The HR department is bloated with unnecessary made-up positions. The turn-over is very high, no doubt due to inadequate level of compensation compared to other similar companies, and no appreciation whatsoever for the hard effort and the extra hours.