Our dealer from my country brings both, Luxman and Accuphase.
I have always preferred Accuphase. Luxman is very good and close to Accuphase, too.
To compare a integrated amplifier with power amplifier + preamplifier isn't very good idea.
If you have big room and big speakers, powerfull amplifiers are always the winners.
Here you can serch from german magazines stereo and audio.
https://www.excelia-hifi.cz/top-1000.html
They always compared integrated amplifiers vs. integrated amplifiers, power amplifiers + preamplifiers vs. power amplifiers + preamplifiers, booksheelfs vs booksheelf, floorstand vs. floorstand and so on.
This is the right comparations to do.
To conclude I would compared Accuphase E-800 with others class A solid states integrated amplifiers (Pass Labs, Luxman, Vitus Audio, etc.).
In my opinion Accuphase E-800 is one of the best class A solid state integrated amplifier on the market.
If you have big room and big or difficut speakers or you listen very loud you shoudn't go with class A. For that is better class AB or D.
Enjoy your systems!