Out of the many dozens of amps I have owned past 20+yrs, I kept Klaus's amps the longest because he constantly refines and upgrades his amps for his customers. I started out with a Stratos stereo and ended up with the top of the line Kismet ref last year.
I eventually had to sell to fund an SME turntable but I probably should have kept it... It's one of the best bang for the buck SS amps for the $.