The 702 has a larger soundstage but it is a little bass shy which makes the highs stick out even more. The he500 has plenty of bass to even out the spectrum and allow a more even listening experience. The extra mid bass adds a nice touch of warmth that the 701 are lacking in.
That mid bass bump became somewhat "too much" of a good thing overtime (take that with a grain of salt, I loved my 500s...).
I'm quite sure I will come back to the 500s in the future, or any successor with wooden cups and true leather (angled) pads
For those (about to rock!) who want a more even presentation, less "fun", more "hifi" sound that simply rocks, get the 5LEs ;)