Time: The job is NOT 8-5 no matter what they tell you - expect mandatory OT and working often from 5am until 7pm or varying hours. A lunch is not often doable. We often took 10-15 minute lunches if at all possible.
Training: Minimal training for most of us. A policy book and a quick once-over with some practice maybe. Some people get good training but most do not. You are expected to get it ASAP and run a study quickly and not to make mistakes.
Environment: It tends to be really clique-ish. If you do not fit in then it won't be fun for you. I don't personally enjoy negative comments about all other employees at all times from everyone, nor do I appreciate inappropriate comments from co-workers in-front of subjects.
Health: Beware that you will come in contact with bedbugs, lice, pink eye, etc. Often.
Ethics, research, and other lines are blurred when money is involved. I have seen this written before on this site about this company. It is true.