Finally: specs/reviews (I constantly read Julian Hirsch during the ’specs era’)...
I settled on: "Is it INVOLVING?"
Sucks you into the content, forget the equipment. Listen for a long session with no fatigue?
For me, tubes are more involving than SS, and then we have the issue: Every time you approach anything: auto; receiver; tt, speakers, coffee maker: is it still a thrill to see/be glad of your choice.
Keeping vintage going properly can be very satisfying, and every time you turn it on, the expectations are high.
It is wise to find a pro to check/repair any vintage components, resistors etc. go out of spec. I don’t ’upgrade’, I just get back to original performance.
I have compared new/old/SS/tube, vintage tubes do it for me.
Also, the vintage FEATURES are a big draw for me.