1. Top HRs would just listen to your problems and issues and then they will go behind your back and tell your manager about it. HR will then gang up with managers and they will make your life horrible.
2. No matter how hard you would work, spend extra hours daily to make project successful, no appreciation, the managers are biased. They will favour their own candidates.
3. HRs rarely comes to office, very difficult to reach out to them. Day when they come, they are busy on phone gossiping and then leave early. Worst HRs, I have seen till date and management here is least bothered about it. Basically they cover each other.
4. They are working on age old technologies. Be careful and sure if you really want to join this company.
5. Micromanagement