1. Crap salary. When I first started, I took a 30% pay cut. Even with almost a decade of experience, I was getting paid the salary of someone who was a fresh college graduate. It took a promotion in job level & duties to get my salary bumped up, and even then it was still 10% less than what I was making at the institution prior to this one.
2. Environment is heavily dependent upon your PI and colleagues. Having a toxic PI or/and colleagues can crush your soul. Depending upon what department/lab you're in, these are unfortunately common and no amount of complaining to HR, the ombudsman, etc. will do anything about it. PIs are small gods and you're nothing but a peon they can control through your thesis or salary. It is, after all, academia. Do your time to get whatever entry-level experience you need for the next job, then get a real job in industry before you're pigeon-holed as a lifelong academic with no applicable skills. If you liked your colleagues and they're unhappy as well, help them leave.
3. No opportunities for growth. Working hard yields the same results as the bare minimum. There is an impenetrable ceiling and it's nothing but annual 2% cost-of-living raises onward.
