Top two most important sound qualities

Like my handle dynamic linearity is fundamental. And I don't mean playing loudly cleanly although that would be true with dynamic linearity. It means linear level changes, no compression no matter how small or how large the change in level. It's one factor that doesn't change when listening to live sound when you change your seat or even leave the room and listen out the door and you still know the sound is live.

You cannot be serious! A checklist makes no sense whatsoever.

Just listen and draw your own conclusion based on what you hear.

If we wanted to be objective, we'd still be worshiping at the feet of Hirsch & Houck...as much as I do miss those guys...😶

OP… “Listing a third or fourth quality without indicating priority is fine, but it's dilutive because it's that much closer to listing all the attractive qualities one can think of.”

Actually, perhaps I wasn’t getting my point across. I was not trying to list many items through my experience… but indicate earlier ones lost top relevance as one learns and understands the real essence of well reproduced music. 

The lifelike reproduction of vocals is by far my first priority. If a loudspeaker fails that test it is immediately eliminated, and most are (vowel coloration---though significantly improved since the early days of hi-fi---remains a problem). Closely following is the reproduction of instrumental timbres, especially acoustic string instruments: guitar, dobro, mandolin, fiddle, upright bass, piano (yes, it is a string instrument ;-), and harpsichord.

As for "hi-fi effects", it is image size and scale. Most loudspeakers sound comically "small" to me, the image of a grand piano, for example, being reduced to a miniature of it’s actual size. It’s like watching a movie on your iPhone. Hearing a doll house-size musical picture immediately destroys the suspension of disbelief.