Marantz 2325, decent power but no speed, good tuner. Too muddy and sluggish fro my taste even after restoration, the Marantz "warm" sound I suspect. Bass-heads and rockers seem to love these.
Pioneer SX-1250 great sounding, excellent bass and quick, excellent tuner and excellent power for 8ohm or 4ohm loads.
Marantz 2285, best sounding amp and pre of the three IMO, detailed, tight, nice accurate unit. Mediocre tuner however, and not enough power for all of my needs.
My Sansui 5000 was too noisy to consider (unrestored), Onkyo/Adcom/other Pioneer/Sherwood not really the same league. The 2325 I included regardless of my dislike for it simply because it's mentioned often, but I feel strongly that the house sound is a matter of preference.
Out of these would choose to keep the SX-1250. It is very close to if not as good a detailed amp/preamp compared to the 2285, but has a better tuner, and its higher power (and 4ohm tolerance) makes it so much more versatile for most any speaker and listening to most any source.
I do prefer separates personally, where my Japanese stuff can't compete, and none of the above have a 2nd phono in (nor cartridge matching) which would be a disadvantage if I spun lots of vinyl.