Noting that I've never used Menzerna PG (or IP for that matter) or OHC, I *have* used a fair bit of H-T EC and IMO it's not as aggressive as one might think.
600-800? Nah, not unless you're spinning a harsh wool pad at some really high RPMs. I did *many* (not just six or eight ) passes with H-T EC/rotary/orange cutting pad on the trunk lid of the M3, and some of those passes were with pressure and some were at >2000RPMS. Still have some marring left after all that...H-T EC just isn't all *that* aggressive. Still good stuff though, took maybe four passes to do most panels on the Blazer to my satisfaction.
But that's with the rotary- it does work well with the PC/4". I added a little 1Z Ultra/Extra to increase the work time without mitigating the cut (the way OP might do) and that's as aggressive as I've ever used with the PC while still breaking down/finishing out well. Just don't expect it to be the liquid sandpaper that it might sound like from the product description
I'll be interested to hear what somebody thinks (of the H-T EC) who's also used the PG and the OHC.