I'm very interested in hearing why the solution for best 2ch sound wouldn't be pre-out to an integrated stereo amplifier? I'm planning to do this in the near future with X-4800H/Cinema 40.
Am I stuck in old thinking?
It all depends on the speakers, the power you need and how loud you are going to play it. I personally am not a fan of AVRs, but even less of combining an integrated amp with an AVR. Now as far as the front end preamp sections and the processor, there is nothing wrong with an AVR.
My problem with AVRs is that I like concert level sound for symphonic music, organ etc. The fact is that the power amp sections of AVRs are limited, as now there are often nine of them in one box driven off a power supply that is too small. In addition they heat up the more fragile components like the processor because they are in the same box. Sure you can use an AVR with preouts to external amps, but the box is still crowded. In addition these AVR amps dislike low impedance difficult loads more than they used to. The fact is, most speakers are nearer four ohms than eight, no matter what the manufacturer says. In any event you probably don't want an eight ohm speaker as it is unlikely to be properly BSC compensated. All of this leads into the reliability issue, which I think is significant downside of AVRs.
So I have always used AVPs and external power amps. In fact even before AV and multichannel receivers, I never used receivers but a separate pre-amp/amp combo.
So what is the downside of this approach? It is cost and nothing else. Everything else is on the upside.
I have used AVPs since the advent of AV. My first AVP was pre HDMI and so that was the reason that was sold on. The next Marantz is still going but stored. The next two that I bought in 2008 and 2010, are still in use without an issue, one in a 2.1 system the other in a 3.1 system. The last AVR is my 7705 which went into service in 2019. I can't really speak to room correction as I don't need it, it can only make things worse. Technically there are reasons Dirac should be superior. My experience with Audyssey is that it is a massive quality spoiler, and the only thing good I have to say about it, is that it sets levels and distances correctly.
Lastly, the Dolby upmixer DD SUR, is now superb, and so good that I seldom listen to two channel without it engaged in my AV room. It realistically creates a sense of space, ambience and perspective from all 11 speakers. In ambient material significant demands are placed on all 11 channels and I'm sure I would have blown up multiple AVRs by now.
So the high road answer to your question is AVP and external amps. I am convinced that in the long run, that is also the cheapest solution. I am particularly trouble adverse. Therefore I design robust systems for the long haul. That way you get maximum pleasure and enjoyment from your major investment.
Members think I spend huge sums, as I have a system with a lot of fine equipment. However there is a equipment here still providing fine service over sixty years.
Purchasing junk, is the most expensive route, and I always encourage going for quality, then you are not replacing equipment all the time.