Ok, so what's your actual point now or what do you want to imply?
Volume controls are no joke and an essential part of amp design. It's not something that just gives you volume, unnoticable crosstalk, channel balance after a certain threshold and then you're good.
What about ensuring maximum bandwith at any position (low impedance too), low distortion, linearity etc? The reed relais gives you plenty that. Of course you can go beyond that. Look at autoformers for instance as controls for power amps. You're at 2k already with some designs, "just" for volume.
Does one lose out? No, the US4/5, v550 are still damn good, but if you want to maximize there is no way around it.
500 Dollars is less than what most people who shop in these waters spend for cables and here you're buying a more critical component.
Btw. The Niimbus which came before the V5, V3 generation came in three versions before production, all quite different in their volume control design. Unfortunately the most exciting (just from a rarity perspective) turned out to be rather lifeless sounding, blunted in the treble, cold. Volume controls always impact the sound.