I just did a quick comparison of my 560 and my HEK v2 (driven by MicroZOTL2 modded by Mojo Audio, with a Mojo Illuminati LPS; digital from Geek Out Special Edition SE/Revive from my PC). Played a 16/48 hi rez track, Suite for 20G, from James Taylor's "Sweet Baby James". The 560 does indeed sound nice, good imaging, bit of depth, engaging sound (do hear a bit of tizziness, rough on the high end, which I've always noted-mitigated by some amps). Put on the HEK; man, there is no comparison. More Air, images have more body, smoother while being more cohesive and "grabbing you by the bottom". Again, I'm not going to address the "six times more expensive issue-you can live happily ever after with the 560 (I did for a long time). Did the same with a 24/88 track of Neil Young's Walk On ("On The Beach"). Same thing-bass has more depth and tightness, texture, there's more width and depth and air between the instruments, despite the increased width the instruments are more "in sync" Neil is a body in space, not just a disimbodied voice. And there is a slight edge to the 560 again...
This was actually a good exercise...when you listen to one set of headphones all the time, it becomes the default sound in your head, and I think you stop appreciating it (think much "upgraditis" is due to this acclamating to the sound and losing that surprise of the improvements noted when a purchase was new). And, I never regretted the 560 at the $900 purchase price. But, do I think I would take the money difference and go back to the 560? Nope! These things are a level up...
My $0.02, ymmv, hakuna matada, and all the other disclaimers.
Peace/=.