I don't have the HTP-1, but do have the anthem avm70 (had/have also, avm60, d2v, marantz 7704 pre and rotel rsp-1576 mkii)
My 2 top were the rotel and anthem..
The room corrections are also awesome in both..
Anthem with ARC and rotel with full Dirac.
Comparing the room correction, they are closer than you think...
My basment is the worse room I could test in.. Unfinished wall, ceiling, etc.. RAW.. Just wood joists and furnace.. and concrete floors .
Going from ARC with avm60 to new 70 is totally different animal... No comparison..
The 70 ARC sounds crisper, detailed, more open.
With same settings on avm60, it sounded like a cloth was in front of speakers
This being said, Dirac vs ARC both sound amazing..
So I'm sure HTP-1 vs avm70, they both woukd sound awesome.
Just comes down to features and $$ you want to spend..
The anthem /rotel were much better than audyssey and marantz... no comparison..