Pros
PRTM has great people. Nearly everyone is helpful, wants you to succeed and will encourage you to be successful, which can be rare in the consulting industry, generally. I worked on extremely interesting projects during my three years at PRTM, and was very happy with the level of responsibility I was given. Additionally, work life balance is valued (maybe not compared to a corporate job, but compared to top management consulting firms) and there is a good amount of vacation time. Management is excellent and has great communication with employees - I always felt like I knew what was going on in the business and what the strategic direction was for the firm.
Cons
My biggest drawback is the lack of name recognition. This is something that PRTM has been working on, but it can be very frustrating, both for selling work and for selling yourself (be it on a resume, with others, etc). For people who know the firm, PRTM always has a stellar, shining reputation and people are impressed to hear that you work there. However, most will not know the firm. Secondly, project staffing can be somewhat subjective. It takes a good deal of internal politics to ensure you are staffed on the types of projects you want to work on.