Just had a quick look, couldn't as yet find the unit i was talking about, but came across this unit
CT70 - EXTECH INSTRUMENTS - TESTER, AC CIRCUIT LOAD | Newark element14,
Check out the technical data sheet.
It's a hell of a lot cheaper at $200 than the other unit, and DOES give both tripping mA and trip times among other bits and bobs.... Also a relatively easy to make your own test lead so you can test GFCI's or whatever, that are not socket outlet based... (It comes complete with a socket connection lead)
Let me know if this unit meets your needs??...