Haven't seen a pirep on this headset so I thought I'd chime in, just in case anyone else is considering the $895 DC One-X headset with bluetooth, which is David Clark's answer to the Bose A-20 and Lightspeed Zulu3. This is the first time in about 25 years I bought a David Clark headset, and I think it's my new favorite. When I started flying David Clark's were the bees knees, a defacto standard. Everyone had them. They were the king of the crop.
When active noise canceling came along David Clark fell off the chart. Back then I bought one of the firsts, a light speed 30-3G... that huge heavy blue one. It wasn't more comfortable to wear than the DC's but of course noise canceling is a game changer. The DC's went to the passenger seat and I never touched a set again until now. David Clark was slow to adapt to the noise canceling revolution and eventually got lapped by Bose and Lightspeed. The BoseX came out and also the Lightspeed Zulu and I bought both. Between those two I preferred the Zulu because it just felt more substantial and the BoseX cups didn't quite fit over my ears. Over time Bose and Lightspeed evolved their offerings and I bought the Zulu 2/3 and then settled in with Bose A-20's as my go-to. The A-20's are spendy but a great headset. I also tried the in-ear headsets like the QT halo but I decided I just don't like sticking things in my ears.
Yesterday I tried out the One-X on nearly 2 hours of flying and I really like it. It's lighter and more comfy on the ears and on the head. It folds up nice and super duper small. I'd say the the noise canceling is just a tad not as good/strong as the A20's, but it's lighter and more comfy and the audio sound quality is better. It's very light on head with no measurable pressure on the crown of your head. The auto-shutoff feature works better which should save some batteries. The audio controls are digital and precise, and can be turned up much louder than the Bose. Also something about the classic green of the DC's goes well with my vintage Twin Bonanza. I think I'll get another set for the flight bag because they fold up so small and light. Overall I think they're great. If I had to stack rank my headsets in order of preference, I'd say at the moment it's DC One-X, Bose A-20, Lightspeed Zulu 3.