Old interesting thread wise AK,
my personal experience, update 2017 , test made always with JBL's 4408, 8 inches monitors, very revealing:
Sansui AU101(price around 150$ refurbished,in good looking condition) VS Topping TP30 or similar Tripath in the 150$ range ( I have tried few of them):
While the T-amps around this price point have pristine signal and in the specific case of the tp 30 a Dac input
the AU101 offer more versatility with the preamp section, and has a phono stage.
I would say if you play often vinyl get the old guy (will go forever and repairs will be cheap)
if you are playing a pc get the Tripath (will fail at some point, buy a new one at little cost)
Sansui AU5900 ( price around 500$refurbished, in good looking condition) VS Rega Brio R (500$ demo version)
This is where the comparison get hard, subjective little details (sound or connection /interface wise) can make a great difference.
I still prefer musically the vintage and pre-controlled versatility of the AU5900 (yes I play the knobs a lot to adjust to music-source/room-behaviours)
but I have to report the Brio has no fear to sparkle and rumble,
while the Sansui sounds better at party levels, more detailed and low freq generous (totally magnificent for his 45 wpc)
the Brio R (mk1) seems superior in liveliness and authority at moderate volumes, has better MM phono stage (vinyl sounds more richfull and open)
is well built and last but not least has a remote, but no headphones. There is a 2017 improved version (mk2) with headphones and few other improvements
but while I am writing this that model cost more and falls in a different price class compared to the previous model (around 1000$)
and I bet if compared to the AU911DG below would have such an hard task to shine.
I would say if you play often (read it is on all day like in my case) get the old guy (will go forever and repairs will be cheap).
if you are playing just sometime, at moderate volume and don't want to get involved in the vintage side of things, the Brio is a good entry level amp.
Sansui AU911DG (price around 1000$ refurbished, in good looking condition) VS Yamaha A-S801BL (900$)
These are two amp built 30 years of distance each other that play very similar,
they have pretty much the same connections (the Yamaha can decode Flacs, Flacs were not there in the 90's so Sansui can't deal with it but CD direct is pretty impressive on the 911),
they both have a remote.
I tried the Yamaha for a week, serious amp. ESS Technology 32-bit ES9010K2M Sabre DAC is a beast.
Hard to say who is better but I can tell you something: the 911 is now 30 years old and in 5 years of my ownership never failed, feels like new.
Will the Yamaha perform the same in the long range? Is it durable? Surely lack of pre out, that the Sansui has.
Looking forward to compare the AU9500 but so far I did not come across anything modern that worth to compare,
I am in love with the tank sorry, I would not be objective on the thing.
I am not saying this is better than anything else, I am saying this is better than anything else to ME

How much for one of those, $1000? Oh man, open the hood and tell me what you think.
Sorry I had to rescue this topic, too much fun reading and when I got to the end of the 6 pages I felt I was ready to read more about people different experiences.
Happy music everyone