I recently tested A) a ca 3500 usd active small speaker system at a holiday house for some weeks, compared to B) my main system at home with amps and floorstanding speakers, costing a lot more. B sounds much better. But I knew this from before, so on this holiday I brought my "secret weapon", speaker stands, to the A system.
The old rule about speaker positioning was dramatically confirmed, more than I had expected. I could micro-adjust the speakers and stands, on a concrete floor (ideal). The A system now turned from "lower mid-level at best" to "fairly good". Good recordings now sounded quite good, and mediocre recordings sounded a bit better - easier to get into, understand - than before.
Afterwards, coming home, I listened to the B system. It does sound much better. Mediocre recordings sound better and many of the bad ones sound less bad. The B system excels in "in-room" energy, with more reverberant sound than the A system. Also it uses expensive tube amping rather than low cost solid state (so it is an unfair comparison, yet interesting).
One major difference is that B has a richer timbre, so it is easier to hear what goes on, simultaneously, at different frequencies. I can listen more deeply into different voices and instruments. The B system is maybe a bit "warm" or "euphonic", but the amps are OTL, known to be quite analytical (within the tube camp). So B sounds almost as "sharp" as the pinpoint A system, only in a different way.
I have not tested exactly, but roughly, I would guess that if 50 percent of my LPs sounds OK on the A system (precisely positioned on stands, only 30 percent without!), 70-80 percent sounds OK on the B system.
So it seems that many poor or non-optimal recordings can be "saved" by better timbre. Better timbre makes it easier to listen for the good stuff, away from the faults (even if these are also often more pronounced in a good system). It makes music more coherent and cohesive. Thereby also, solid state and digital hard sound can be counteracted, if not fully corrected.
At the same time, my experiment indicates that you don’t need costly speakers to improve the sound. Much can be done with the speakers available. My guess is that many here at Audiogon would re-discover their LP collections (or streaming), if they worked more with the speaker positioning and other acoustic control. If you position (and maybe damp) your speakers right, you will get a richer and wider timbre. This is an overlooked dimension I think. Forget about exact flat frequency, timing, PRAT etc, - instead, go for the timbre. Not sure about this - but maybe a way forward.