In some ways build quality was better, in other ways not. The chassis and casework is usually heavier gauge, fewer ICs and more discreet wiring. Pots and connectors were chassis mounted. Nice wooden cases. But the components were built to lower tolerances and are not as well matched, and some of the technology available in new amps hadn't been invented yet.
I'm guessing the KA 5700 cost about $350 back in the day. That would be around $2500 today. For that money, you could buy a brand new Yamaha A-S1100 (complete with VU meters) that would certainly out-perform it and have probably better build quality. I'm guessing the Yamaha would give the Luxman a run for its money (of course it all depends on your speakers, room. power supply, etc.).
I can understand how a vintage piece in good working order (new caps, etc.) would be a reasonable "stop-gap" option (if you can find one at your price point). It could also be an interesting DIY project, if you are so inclined.
My gear is not very glamorous. Being of modest means, I selected for sound quality over aesthetics. But inside those plain looking steel cases are some excellent electronics. My speakers look pathetic, but they sound good. The turntable I am currently using is certainly not styled to my taste, but it works well. Nobody is impressed when they look at my system.
I certainly would not be satisfied with a $225 Emotiva amp. My stuff is considerably more expensive. It suits my needs. However, I doubt that insanely expensive stuff sounds much better than what I have. At a certain point the law of diminishing returns kicks in. It's like my $250 watch. Stainless case, Swiss mechanical movement, Sapphire crystal. I doubt that a $10,000 Rolex keeps better time. But I wouldn't mind having one!
