How good can it get, really? - my stereo sounds amazing!

The quality of your ears, in relation to home stereo, is limited by the best system you have ever heard. Before you hear a system that is a revelation you dont really know what you are missing, nor how your home system compares. 

When respondents get on this forum telling you to ignore cables, tweaks and room treatments take a look at their systems and then choose if you should listen or ignore. Many enthusiasts have already made a decision about such things and any communication with these members is casting pearls before swine. 

Like audiozenology states, furniture is no substitute for room treatments. FACT!

Right now I'm listening to an Erato recording of Renaissance Music streaming via Qobuz and my Mytek BB.  An older Primaluna integrated (new 6550 tubes) and a pair of cheap NOLA Boxers. No tweaks.  Cables, etc. commensurate with the rest of the system. No room treatments but a good room with careful speaker placement. The soprano's sound is absolutely delicious. Yeah, I'm happy with what I got.

Take it from someone who has made a ton of stupid mistakes AFTER he was content...
STOP AND ENJOY AND BE HAPPY.

Fortunately, I've succeeded in assembling a system that makes me very satisfied... And I'm stopping.

Like audiozenology states, furniture is no substitute for room treatments. FACT!

Actually that kinda depends on how and why the furniture was built. Read, its quite easy to design and build sound room specific furniture, and decorating features, that serve a dual purpose, and produce an acoustically correct environment that doesn't scream man-cave ( or cost a mint ).

Without wishing to be overly dramatic or mysterious one of the very best things you can do sound wise is take all the CD, DVDs, LPs and books/magazines out of the room. No, they do not act as diffusers.