I did an A/B test on Amp5 and Amp10 last weekend and I didn't notice a difference at (soundwise) all. I have done this without and with a toggle switch cause I can't really tell if there is difference. I initially used one (then a pair) speaker with two amps and thought there is something wrong with the setup, everytime I toggle the switch to other Amp it's like nothing happened.
Then, I replaced the input caps 3.3uf with Clarity SA (still trying to get the mkp1837) caps on Amp10 and still didn't notice a difference at all. I don't know, maybe my ears is not as good as somebody else but if there is a difference I'm positive that I'll notice it when I toggle the switch.
Now it's time for me to sell all my Amp5 (16 channels) and two Amp10B once I get the bill of material to finish it cause I'm sure that I won't hear a difference with those three Amps. I'll keep the 10 channel Amp10 for my Orion.