Any idea which headphones I’d like?

@ghdprentice is that a Woo Audio tube setup, by chance?  I was looking at the WA22, and WA5LE.  I’ve owned tube pres, and it takes some time and coin to get the right tubes.  Those 300B’s, everyone says you really need to have the WE’s as a baseline and reference, because they’re the gold standard.

How have you approached getting your tubes dialed into your preferences?

What sound characteristics are most important to you in headphone listening, and what do you dislike?  This info would help narrow things down considerably. 

Everything focal makes right now is pretty good. The Focal Elex on mass drop is only $600 and is every bit as good as the others. The Clear MG is pretty great at $1500. Don’t buy sennhieser HD800s, you will hate them…. Ear tweeters.
I have had many of the highend headphones and only keep around the focals (and Grados) at the moment.
Audeze headphones have some odd coloration in the mids as do most planer but wow the bass is special. Try to demo them.
You could buy a few off Amazon and crutchfield and just send back the ones you don’t like.
The nice thing about headphones is you can own a few pairs with different sounds.

edit:

I see you have owned the Focal Clear. Honestly this is 95% as good as it gets with headphones. If they did not do it for you, headphones might not. 
Some brand generalizations below. 

Focal=good all around 

Sennhizer HD800=best soundstage (bright needs tubes). 

audeze=amazing bass but odd mids and rolled off highs. 

highfi man=weaker bass than the audeze but a bit more soundstage. 

Grado=the horns of headphones, love them or hate them. The PS500e is pretty great with flat pads

Fostech= subwoofer type bass. 
Mrspeakers=somewhere between audeze and hifi man. 

Focal Clear MG Professional.