Top vintage receivers vs. modern high-end equipment

I am considering pairing an old amplification system to my JBL Paragon -- the idea of getting an all vintage system is very attractive to me. Among other things, I am looking into classics such as the Pioneer 1980 receiver or the Marantz 2600. Does anyone have direct experience in comparing this kind of equipment (very high-end but 40 years ago) to current high-end equipment, imagine an integrated Pass Lab amplifier? How do they stack up? Thank you. 
Well, I asked about receivers because I did not want to leave any stone unturned: I am not familiar with vintage receivers, and I thought that perhaps there might be a hidden gem in there. It looks like most people would go separates or perhaps integrated amp. I am leaning toward the Marantz or McIntosh separates. It's interesting that some folks rave about Marantz Model 7, which others think it's really nothing special. I am still tempted to go modern (thinking about Pass Labs Int-60 or a class A Accuphase integrated amp, like E-550 or in the tube camp one of deParavicini high-powered ones, like the 899 or similar)...but the idea of having a full vintage system is probably more right. 
New Accuphase Class A INT coming out in 2 months E-800...50 Watts into 8 Ohm
Sansui 5000X (circa 1969-70) and Marantz 2270 (circa 1970) are two of my vintage favorites.  Don't get the Sansui 5000 or 5000a just the 5000X.  These models had a lot of problems and recalls.  Most of the early Marantz are good but not the B series.  Kenwood always made a good receiver and Harman Kardon with dual power supplies did also but often overlooked.  Pioneer is OK but middle of the road and many models have a problem with the protective relay circuit causing the set set to click on and off and a lot of tech time to repair.  Some powerhouse companies made great tube amps and early receivers but couldn't make it into the solid state age with any good units (Fisher, H.H. Scott, Sherwood, Pilot).  For a tube receiver I would pick the Fisher 500C.  
Add me to the list questioning your decision to purchase a receiver.  Many stations stream their broadcasts and IMO a decent streamer from Bluesound or  used Auralic Aries (I own an Aries mini) will provide better than or equal to SQ of a tuner. Grace digital also has a selection of what I consider entry level tuners but still mostly equal in SQ to a receiver. 
As for age, I have an LFD Mk3 which has to be 20 years old and I am extremely happy with the sound. I am sure there are newer integrateds that sound marginally better, but I cant justify the price. 

Look into Nakamichi. I have a Receiver 2 which is amazing. The Receiver 1 at 80 watts would be even better. Both have great MM phono stages; but they are early '90s, not '80s.

The TA series from the 1980s designed by Nelson Pass was legendary

The TA4A even has a MC input!