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
I also suggest the Sansui AU-717. My roomate had one and I still think it was one of the best sounding setups I ever enjoyed. Maybe a little sensitive to low impedence loads as once in a while it would go into thermal protection after extended enthusiastic sessions driving double Advents. Always cranked back up after a cool off period and sounded great again!
Tandberg makes some of the nicest and best-sounding integrated amps. And they sound worlds better than the other ones you mentioned. Check out this 3012A right here on Agon:

http://www.audiogon.com/cgi-bin/cls.pl?intatran&1231606941&/Tandberg-3012A-Integrated-Amp.

I also really like the NAD integrateds, very ballsy sound. Check out this C272:

http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1231703798&/NAD-C272-

-RW-
Ya,Sansui AU717 integrated, can't go wong.
Musical and powerful,with good detail,smooth also.
And it looks cool!
USblues is right. Get a clean one, then plan on putting some more $$ into it to replace old caps, add bypasses, have all the controls cleaned. Sansui, Pioneer, adn Kenwood made some complete dual mono integrated amps before it was cool to do dual mono.