How do you know when a stereo sounds good?

As a relative newcomer to audiophile the most important characteristic to me is imaging, starting with strong center image. Next is clarity, I believe neutral tad warm.

I'm working on understanding tone and timbre from midrange up to treble. I enjoy my Yamaha A2080 AVR to R3's and Ryhtmik sub but I believe the treble of the A2080 although clean and clear, may not be butter smooth. Sparkly with edges maybe, but it images well which is my primary attribute for good stereo. 

It seems my desktop electronics may have a slightly smoother treble, it being PC Tidal FLAC > USB input to Schiit Modi 3+ > Emotiva BassX A-100 > LS50 Meta (and I have tried the R3's there also).

I believe stereo is ultimately subjective, but how could an audiophile enjoy stereo if it did not begin with some semblance of quality imaging?  It could be cold neutral imaging, to warm side of neutral imaging.  But must have imaging.  

I had about a ten year period about 25 years back or so where I made impulse purchases without doing proper homework and my system sound quality suffered. Learned my lesson. I am pretty good at resisting impulse buys these days but the urge is always there to just go nuts sometimes so who knows what the future holds.

The worst sounding system I ever heard as far as expensive gear that sounded bad as opposed to the cheap stuff that is typically more suspect was in a very high end NY shop. Luxman driving Peak Consult. Uggh. It was not good. Something probably awry but the salesman was happy to demo it. In another room there was a VAC/Magico setup that was the bees knees. Go figure! Different strokes?

It sounds good when you forget that you are listening to a sound system, and just get lost in the music.

It sounds good when you forget that you are listening to a sound system, and just get lost in the music.

That happens more often in my car than anywhere. Probably the result of there being no distractions (other than driving of course).