I also still own the HD800 but I sold off my amps that could drive it properly. I had the Questyle CMA800R and Bottlehead Crack, but I think I ended up deciding to just keep a more lightweight setup. I regret selling the Crack because I remembered the tube amp paired nicely with the HD800.
I originally got the Edition X because it was easier to drive and could be used directly with my phone (this was before the headphone jack got phased out). I remember I got the Bakoon amp because it had an unique current driven topography that worked well with planar magnetics.
I was comparing the sound from the Edition X through the Bakoon vs. directly through the Roland, and it's crazy the difference it makes. Through the Bakoon, everything sounds more 3 dimensional with distinct layers for each instrument and vocals, with the background being blacker as well. I'm actually quite surprised how much the amp improves things. They sound like two different headphones or at least a higher grade of headphones in the same line.
I'm glad I kept something decent for myself. Next I'll need to look into picking up something that can properly drive my HD800.
I just picked up a used HD800 earlier this year and its become my daily driver. I've always said I prefer darker gear so I was quite shocked how much I like it.