Vintage integrated Amps. What to look for?


I am sure there are a few that have done what I am thinking of doing and would like to get some opinions on doing so.

I have for years always had separates, and good ones at that. Now while I have always been happy with what I had I have always had the urge to try some vintage gear.
I thinking of selling my separate preamp and amp and getting an old Fisher, Marantz or Sansui integrated amp. I have read allot of good things on the Sansui 20000.

Who has done this and were you happy with the change?? What were or are your likes and dislikes also what vintage integrated amp's did you look at? consider buying or did buy. I would like to have a phono stage on it.

Thanks
btstrg
Do it.Get a mint cond model of your choice for ridiculous money on ebay.Like 150$,put another 150-200$ for caps,parts etc. and you will have a very nice unit that will make you ask"Why did I spend that 10K?"Remember the speakers must be easy to drive.I just did it with a Sansui 5000 and another model which escapes me just now.The sound was 80-90% of what I had with new mid-fi stuff.I am now playing with Mcintosh which is much more expensive that the classic Japanese stuff so the beat goes on,sometimes in a circle,have fun,Bob
My suggestion: Sherwood, integrated or receiver. Often on ebay, very musical, full but airy.
Sansui Au series ..Built like a tank and sound great.......
I am using the ( 2nd system ) AU 517 Int. Nice phono also...
I would add the Sony pieces, vintage 1966 to 1976. These pieces have superb sound, build quality and phono stages, and were built to compete with the likes of McIntosh and Marantz. The receivers have superb tuner sections. Look especially for the 1120 integrated. Matched capacitors!