I thought I would jump in here to mention a couple of headphones not covered yet.
My main HP on the Mainline is the Focal Elear. These are very comfortable and have a well balanced sound - excellent mid-range (where we all live), good, accurate bass and treble. I'm not a bass head and I prefer phones and speakers that are not overly bright, so the Elear is a good fit for me. For a closed-back HP I prefer my VISO HP50s. I find closed-back phones and IEMs somewhat fatiguing due to the "hard panning" nature of headphones in general and the closed-back design in particular. The HP50s were designed to emulate an open speaker like sound.
I use a Senn HD600 exclusively on the Crack in my home office. These are the only high impedance HPs I have so I cannot compare other high impedance phones for either the Mainline or the Crack.
I have played around with the idea of a cross-feed circuit to minimize hard panning and make the phones more like open speakers. I use a Leckerton DAC with a cross-feed function with my IEMs and I can listen to them for hours without fatigue. Tracks that are mixed with speaker usage in mind can survive excessive or hard panning to some extent but head phones cannot. Luckily most audio engineers are aware of this and watch the level of panning knowing that our brains attempt to resolve a stereo signal to the center. If someone has experience with implementing a cross feed circuit in BH gear, please share with the BH community.