Found a lvl 70 item on PTR just now:
Two things that makes PTR less fun than current vanilla D3:
1. It´s easy (hardest difficulty is too low, hope they fix it soon)
2. Monster density has been lowered. Why? change it back to live version! Or are we suppose to go back to grinding Act 3 again?
I believe monster density is still the same as before the adjustments in current vanilla MP0, and I think it's back up once you switch to Torment difficulty in RoS.