I just opened my Liquid Spark yesterday and set it up, it’s incredible people slept on this amp! With my HD 800, high gain is almost at the beginning of the volume pot travel! It’s maybe not the absolute last word in detail, but it feels clear, and it has tube-like soundstage depth and smoothness without the hassle of tube buying or interference.
I think people overestimate power needs, and undervalue the tonal quality of amps and upstream gear. The headphone in my collection that requires the most power is the Fostex + Dekoni Blue (a T50RP mod), that may only have about a 60 Ω impedance (the mods make it slightly harder to drive than a regular T50RP mk III) but really people ought to look at the Sensitivity specs to see how much power they need. Speaking generally, a power calculator can give people an idea of how much power they need to reach a particular sound pressure level (volume measured in decibels), like this one:
https://www.hear.audio/2019/06/01/headphone-power-calculator/
The Liquid Spark was a $99 amp, and a deal at that price (I impulse bought it at the $33 sale!). Apparently, Monoprice is restocking it next month, at least that’s the rumor.