If they are both as clean as a whistle I doubt you’d notice much difference. The draw for me would be that copper needs to be cleaned so frequently, silver would take much longer to tarnish so would end up performing better, for longer.
(I should point out that I don’t really squonk but use mech tubes, and find that aluminium, copper, brass and stainless steel all perform pretty much the same. Just that the copper and brass are s pain to keep clean.