I think all three Weber heads are the same except for the coating or lack thereof. The ARC coating, a kind of chrome coating used on medical instruments, as I recall, seemed to pick up certain flat-lying whiskers quite well. But I like the DLC as well---it was just that the ARC was a little different and seemed to perform a little better. I only have one Wolfman Razor, but I am on a wait-list for the WR1-DC, and of course I've requested a slant.
I don't know that I agree that there's little room for innovation in head design, BTW, something that JugV2 said in another thread:
Really what changes or ground-breaking advances can they make in 3 piece razors?
Stainless steel shaft...decent head...vary the weight a bit maybe for a different result and watch the fanbois gush over it.
Meh.
First, there's the slant, and we have two variations: the twisted blade (like all the current slants except one) and the untwisted blade (the one exception: iKon Shavecraft #102). And then there are adjustable possibilities, though in modern razors the Progress pretty much has that locked up. (I consider the Progress, a cost-engineered Apollo Mikron to my eye, superior to the Futur or Vision.) And there's the dual-comb design, introduced by iKon in the OSS. You have the two-piece razor with a rotating handle (Pils and a couple of iKons). You have lots of variation in head design: Pils, iKon's various heads, the ATT approach, Wolfman's razors, even Parker with the 24C and 26C, plus lots more.