I see maybe the Burson Soloist as its direct comp but to me, the M19 sounds better even with the Soloist in poweramp mode.
I’m still a relative noob in this hobby but when I started out, I bought into these popular websites and youtubers claiming that DACs dont matter or that Topping A90 is the best measuring amp, with the implication that it reproduces great sound.
Only after hearing/testing for myself (mostly midfi gear) did I realize how far away from the truth these statements are.
And to think I bought my M19 from a fellow headfier for slightly more than what I paid for the A90 new, I now know to trust and rely on my hearing than some internet experts, measurements, or even price as an indication of sound quality that fits my tastes.