Cans are funny, evey ear is shaped differently, but I do not doubt that those are awesome.
There is a spatial thing about nearfields, as well as a physical component.
It is one of the reasons that "shockwave" head sets work.
That said, I do not doubt that someone can master well on headphones, but it is not standard practice.
Why not try it a few ways, listen to your work on a few different systems and see if you hear differences from your mastering rig ?