I just got a test sample of the HP200, courtesy of hifi-headphones. I'll be working on a full review soon, but here's a couple of quick thoughts...
So far these things sound really great! Only tested them in a noisy office environment so far, not the best test condistions, I know. I will report back when I've had a bit more time with them. I need to test them with a proper amp, so far from my phone (Galaxy Note 2) they sound very good (20 Ohms), but surprisingly warm and with significant bass slam for an open back.
All the big cosmetic concerns I had with the HP100 seem addressed here. Ccheap, finger print magnet, plastic cups replaced by gorgeous metal grills and pretty logo. Annoying coiled cable replaced with a straight 1.2m plus separate extention cable - win win!