Pros
In most positions you have a lot of responsibility with little oversight which means that if you're a self starter and you learn by doing you will grow a lot. The breadth and depth of exposure would be hard to find elsewhere.
Kontras
The org lacks management capacity and if you need constructive feedback from a supervisor to feel like you're on the right track, you probably won't get it (unless you happen to have a good manager). The organization itself does not value management skills and therefore most managers do not know how to manage their supervises properly. There is a lot of talk about IPA's people being its greatest asset but that sentiment is not reflected in company salaries, benefits or decision-making processes. The culture is about working like a dog and then moving on to a phd program. Tenure, hard work, dedication are not particularly recognized or rewarded so turnover and dissatisfaction are high.