Did the Old Receivers Sound Good?

No, they don’t stand up to todays gear.

Ive recapped/rebuilt several Marantz units myself, and while they have a certain charm to their sound, they don’t stand up to critical scrutiny in listening tests. 
 

Was just comparing a Marantz 7T with a Cary SLP-30 (Both had full recaps done by me recently) And while the Marantz is an impressive performer, the Cary is a more refined unit. Granted, I’m comparing apples to oranges here, but the question was about modern/vintage. And by some standards, the Cary could even be considered vintage now.

Yes, yes they did sound great, and many still do.

Memory based on sounds is faulty. Unless you have one with a modern component to compare, it's not a fair fight.

Had a real nice marantz integrated bought new in the 70s, very nice well rounded sound as stated by some here, but nowhere the clarity of today's equipment.

Bought a new Sansui AU 717 in 1978. Double mono design. I thought it sounded great.

Back in the day, I had tube and SS separates and a couple of different tuners and all of them were the weakest link in my system.  Having said that, David Hafler and Bozak sounded pretty darn good back then.