had a 1 hr and 44 min session while the sound is amazing these are uncomfy after a while they clamp quite a bit and have some head aches around the side and top. the pads are nice and soft but the clamping pressure is a problem. i'm hoping it eases up as comfort is a deal breaker for me due to these being my main portable.
You can stretch the band on the top. There is actually a PDF that Dan posted somewhere that shows how to increase the clamping force. In short, you just lengthen out one side and shorten the other, then hold onto the sides and you can stretch each side individually to reduce the clamp. It has possible downsides though. If you do one side more than the other it can cause some discomfort, and you could alter the bass/isolation a bit. Anyway, I like a little less clamp myself so I stretched the band out just a bit and it worked fantastic.