@runwell trying to understand your points: "build quality, accuphase is amongst the top one”; "the sound, accuphase is not the top one”
Accuphase has many SKUs, “cheaper” ones are not top performer comparing to other brands reference designs. Wondering which Accuphase model number you are referring your post to?
Having 30+ years behind checking/testing sound of different products I found Accuphase is the best comparing to other brands on combined metric: build+reliability+amortization+esthetics. Also, Accuphase amps are able to drive very "difficult” speakers without sound quality impact, which technically can be explained by higher phase margins at realistic load impedance, in very wide frequency range (5Hz..200kHz).