I am thoroughly enjoying the HE-500 with the Project Ember and a Russian valve that I have yet to figure out what it is. It lacks a bit of the slam and dynamics that I've managed out of some powerful solid state amps, but it has good synergy otherwise, though it is very valve dependent. I remember the Sunrise 2 as a bit more romantic and musical sounding, but its definitely not as powerful as the Ember which is more solid state like in its presentation with a bit of valve seasoning. @cskippy, definitely agree, I do think the lack of mid bass is something that will bother some, especially if you compare it to something like the HD650 (too much imo), but the HE-500 does pair nicely with a DAC that has a bit of a mid-bass boost like the older Thetas of which I currently have one. From what I've read the Schiit Mimby has a similar slight boost in the mid bass, so a Project Ember + Mimby setup might be something interesting for those looking for a good value for money solution and looking for a bit more mid-bass presence.