He does plenty of competitions. I'm pretty sure he saw a higher score with the Korean. All of it can't be in his head.
Well, actually, it can. I will say that there can be differences, yes. Are the differences better or satisfying a predetermined notion that just won't die. I have a Surge SP-2000.4, Korean. I have hooked it up to my test bench and done A/B comparatives between the Surge, A Focal FDP 600.4, Helix M FOUR, Pioneer PRS 4200FD and a Stereo Integrity SIQ 125.04 very clean direct to signal class A/B amp in a pretty quiet sound deadened room and while their may have been slight nuances in sonic signatures, not me nor my 3 musician buddies could muster better than a 50/50 split on consistently picking which was which. I play Drums, Keyboards, Cello and bass guitar and think I have a halfway decent ear for those nuances you'd typically be looking for between them.
That said, I will point out something that all four of us did notice on another A/B test. When comparing the Taramps, soundigital full range full bridge multi channel amps with the Pioneer and the Focal FDP 600.4, we all felt that the Taramps was slightly duller than the others. Just seemed to lack a certain sparkle in the upper registers. It's entirely possible that was a result of the rather high noise floor present in the Taramps as opposed to the others.
Now when we compared the taramps BASS, the Soundigital EVOPS and the Surge 4K monoblocs, we had an even worse score that with the other test only nailing the differences probably 25% compared to 50% on the first test.
In conclusion, we thought the biggest differences here were not due to class or topology (except for the Taramps full range and that is still subjective) and likely it had more to do with the cost and quality of the product. The more expensive units got picked more often than the others, pretty regularly. in that sense, I would say that any of the monoblock amps would do equally great in most everyone's daily driver and even in comp systems. We could not hear a difference in the dual Si SIQ 12s in a my friends box tuned to 29 hz. At the end of the day, looks like, to a point, you still get what you pay for.