Its funny - when the choice in single-ended portable amps was between Stepdance, Lisa/L3, Pico and various amps from RSA and iBasso, I remember thinking 'Whoa ! Too many choices !'. That situation has worsened, IMO - in addition to your glowing recommendations, we now have the ALO Continental/National, there is a new Leckerton and Justin is talking about making the 'Power Pico' a reality. Great .....
The obvious answer is a meet where ALL of these amps are assembled in one place. That, or be prepared to spend ~5K USD on a drawer full of portable amps. :rolleyes:
(the above assumes that you aren't also seduced by the balanced portable amps - depending on the degree to which you wanted to go crazy with that, you could easily blow your amp budget out to 8K USD, not counting the cost of source/headphones. No question that it would be a blast, but I can see why longtimers like Skylab moved off to concentrate on desktop kit)