I got mine today too, so I can answer some of the comfort questions.
The clamping is somewhat hard, but it's not like it hurts you or anything, it's harder then my DT770 Pro for sure, but my DT's have been worn for more then one day so maybe the Shures will loosen up.
The fit on the pads is good, but the space inside the pads is less then my DT770 and my old Senn HD595. This coupled with the clamping makes a uncomfortable pressure on my ear. If you compare it with the DT770's the outer edges of my ears doesn't even touch the driver, but on the Shure's they do, which causes the pressure.
The earpads themselves are extremely soft and comfortable, a lot better then the velour pads on the DT770's. I hope the clamping loosens up a bit, and im sure it will since I've experienced them getting a bit more comfortable during the 10 hours that I've owned them.