Neither SSC Vader really had a great helmet sculpt though and were oversized, the Medi seemed better overall (have never seen it in hand) but that's 1/7 and it had QC issues. The Hurricane/Kaiyodo ones seem to be the gold standard for custom Vaders but no dome really works perfectly with the Kaiyodo (Hasbro too big, SSC a tad too small, but Hurricane is working on a new one.) Matrix's is the only custom Vader where someone took the Kaiyodo kit all the way and I'd say that still edges the HT Vader slightly to my eye in the "man in a suit" test, though it's ESB/ROTJ not ANH.
I guess the bottom line is, previous licensed 1/6 Vaders haven't been all that great really, and finally one comes along that's got a really very nice facemask/dome (obviously the toughest part of a Vader,) but the chest armor, gloves and sound (and other nitpicks - belt, wired inner cape) shouldn't have been issues at $300. I do love the pics of the HT Vader where it looks just like the legendary Marmit Vader.