I demoed the HP50 today and I was really impressed by them. I usually use the Denon AH-D600 and I have enjoyed them but I know the old D2000s were supposed to be better. I read on Innerfidelity that Tyll prefers the HP50 to the Denon D5000. So I decided to listen to the HP50 as in theory these would be much better.
In short, they are. They're not as comfortable as my AH-D600 nor do they have the same spacious sound. I really enjoyed how the HP50's mids are more forward than my Denons. It didn't go quite as deep but it was much more controller and textured.
At work I regularly use headphones up to 6 hours a day easily. The Denons excel here as they're just so comfy. My work headphones also have to be closed back.
I also listened to the B&W P7, I thought these were ok, nowhere near the HP50s though. I also listened to the Sony MDR-1R, these were good but not as enjoyable as my Denons. Finally I also demoed the AKG K845BT, I only had about 20 minutes at the end with these. I enjoyed them, but didn't quite find time to really figure them out. I've previously heard the Momentum's and they were too small for my ears.
So in short, I'm torn on the HP50. The headband applied too much pressure on the top of my head and the ear cups were uncomfortably small.
I don't really know where to go from here. Surely there must be an answer? I've heard good things about the Fostex TH-600 but they're a bit of a step up price wise.