What would be some good training spots for level 200 when Unleashed is here?

No, if you stood in one place with a pet the most you would get in a half hour is whatever drops within your vicinity which isn't going to be more than like 20 or something.

Depends on what class you are and what equips your pet has. For me as a melee class with 100% stance and a pet with Wing Shoes and Binoculars, if I stay on the left side of the vac machine, all drops fall where my pet can reach them.
It does mean I get practically no kills (and no drops) while the machine is off, but such is "paperweight training".