i have an m400 + sp400 stack, sonata hd pro, sonada bhd, m500, geshelli archel 2.5, sabaj d5, a50s, d30pro, meizu hifi pro, all in different systems, applications. these power an hd800s, elex, hd600
the m400 + sp400 stack is ridiculously overpowered. it was a splurge on my part to be able to handle anything that my 4th headphone hanger can throw at it (want to try an he-6v2, but i have a strict 4 headphones at a time limit). the sonata hd pro is fantastic and serves as the dac for my a50s in the bedroom. desktop performance for almost nothing, and the a50s can drive anything balanced and most things unbalanced. the sonata bhd is something i just picked up for portability of my hd800s (i am out of town at the moment). my partner uses the archel 2.5 and m500 as the system for her audeze lcd1, the sabaj d5 is in my living room connected to the tv. the d30pro is a preamp for my genelecs. the meizu got lost behind a couch for 6 months..
i would be hard pressed to ABT any one of these dacs and HPAs. the only time i could tell the difference was with the m500 driving the LCD1 alone. it was reaching for current it didn't have, i think. insufficient power is the only time i can ABT anything. in fact, some of these are going up for sale (a50s -- i stopped using the bedroom system, m500v1 -- just the wrong form factor to match an archel) because they're superfluous, and no other reason.
i think i can say with authority that there is no difference between high quality well reviewed panther parts reviewed on this site except for power and feature limitations.