Pros
Forrester is a relatively small company that tries to foster an exciting and collegial environment for its younger employees. The senior management goes out of its way to offer transparency in the company's strategy and performance, and it often does so with a great sense of humor and vitality. There is always opportunity to take ownership of a special project, advance a new methodology, or own a process.
Cons
Forrester often thinks and tries to act like a billion dollar company, but its execution always resembles that of a small company. This translates to a constant state of very high expectations and few resources to realistically pull anything off well. This often trickles down to frustration as the worker bees must "make it work" and deal with tactical headaches. Salaries are very low, especially for recent graduates and negotiation is not possible. The expectations for quality, volume, and turnaround of work are unreasonably high in my own experience, given the lack of compensation. In general, competent employees are overworked while others slide by. The opportunity to take on more responsibility and do additional work is always available, but only if an employee is willing to work much much more than 40+ hours per week. In time, taking on more work is "rewarded" by a reset in manager expectations such that the overtime being put in (and not compensated for) is considered normal or the low bar. Standards for promotion vary wildly for the same positions around the company, leading to some animosity among junior research staff. At times it seems some are rewarded because they market themselves, almost shamelessly, to get ahead.