They are very good amplifiers. My opinion is they are better than the MC30's-
I've owned both W5 and MC30.
Over all, if I had to criticize W5 I'd say they are a bit on the dark side in
terms of coloration- sort of a cello as opposed to violin.
An easy improvement is to replace the coupling capacitors with good modern
ones. Ned Carlson at Triode electronics usually has a good stock of reasonably
priced good quality capacitors.
BTW the tubes are quite valuable, and very good.
AMNYC