Amps from the 1980's -- What gear holds up sonically? Reliably?

I've had several models of Sumo amps through here in the past 20 years, of them 3 Nine Class A's including the prototype. None of them needed recapping (per James Bongiorno who I befriended in '98) and all of them sounded great. We did mod the Nines to a newer opamp and IEC socket but I also had an Andromeda, a NOS Gold, and a NOS Power, the Power especially took my breath away. I still have the silver-faced rackmount Nine plus a Rowland Model 5, a ML no.336, and a Bedini 250/250 working perfectly now as when they left the factories. Only my Mac 2105, probably 70's, needed new power supply caps (oversized ones definitely gave me better bottom end). I also use a Nak 420 power amp in my studio from that era. There's also a Yamaha P2200, BGW 750D, QSC USA 400, an Audionics PZ3, and a hunkering Crest 4001 in the garage, all still work fine. The only other amp I had to replace caps in was a Harmon Kardon Q50A from 1964, rather older than these. Quicksilver caps were a huge upgrade but we also bypassed all the junk stages (tone, filters, blend) and the thing sounds awesome. Only a Merrill Veritas monoblock pair ( here for review, $12K) exceeded these but I didn't have the Levinson then which is my daily driver. I can't believe some people feel all amps sound alike (AES!) but then I hear cable differences too, so sue me. ABX is deeply flawed. Go with your ears...after a reference check multiple times. Blah, blah...