The Audio Technica wing system is super comfortable, though not very stable. I would say any of them are easily more comfortable than the Shures.
The Shure pads are very soft and provide good isolation. The gripe with the 840 is the lousy headband. It's huge and heavy and has a stupid unnecessary rubber chunk in it, which is also somewhat flat and places a lot of pressure on the top of your head. If you have a wider head that contours just right, it's quite comfortable. If not, you get all that weight on the top which is very uncomfortable.