Went back and listened to a bunch of the videos of Alexia2, Stella, Magico and 20.7, across the different songs (not necessarily straight-up comparisons across common songs, but rather an amalgam).
I like ron17's analysis - can't really argue with any of that.
But for me I'm not so focused on the things he was. I went into it not even knowing what I wanted to focus on. I just let the presentations guide me and tried to ID the biggest differences I heard - probably at the end of the day this points me to those things that are most important to me. Plus I'm kinda hungry right now and wondering what I'll have for dinner tonight, but I digress.
What really stood out across the presentations was the difference in dynamics and what I'll call muscularity or slam. That kick you in the chest slam that just grabs you by the throat and says, listen up mf'er, this is how the music is supposed to sound. Anything else, just take that weak sh++t and move along.
If a speaker doesn't have it, and I mean really have it, it cannot rise to the top for me. All of the other stuff (tonal balance, clarity, coherency, soundstage, imaging, midrange, treble, bass, balance, ....) is important too, even necessary, but dynamics and muscularity is a deal breaker for me if it is missing. For others, it won't be as important. I think though, for WC it is just as important to him as it is to me, and I think his speaker choices and length of ownership bear that out.
So, let's describe it in terms of a restaurant analogy. Wait wuh?
20.7: This is the little known restaurant you book with your wife, not having high expectations, but you get there and it is all a lot better than you expected it to be. The food was good, as you expected it to be, but the ambience and fun factor was much better than you expected. The service was top notch for what you are spending - good experience. You leave having had a great time and you will be back.
Magico: This is the highly regarded Mexican restaurant that you've been hearing so much about, and you have high expectations. But you get there with your wife and the menu that is handed to you has all Indian dishes. You're like, WTF?? But you order anyway and the Indian food isn't bad, not great. But the weird thing is the entertainment is some hula dancing team. None of any of it makes any sense. You leave going, what just happened here??
Stella: This is the black tie steakhouse, all formal, little stuffy. You and wife enjoy a fantastic meal, and the entertainment in the corner is a violin player, who is very good (technically really, really good), but, you know, it's a violin player. You look around, and everyone is sitting properly at attention, some watching, some looking at their phones. The music isn't very loud, and it seems overly polite. You leave thinking, well, that was really expensive, and the food was great, the entertainment level was I guess okay, and I think my wife liked it a lot, but ...... just not really my style.
Alexia 2: This is the top BBQ joint in St. Louis or Austin, with the best rated ribs and brisket in the country, and the entertainment for the night is a kickass blues band. You and your wife enjoy an amazing BBQ spread, you eat and drink way too much because it is just so good, and then the band starts and everyone in the place starts dancing, the drinks are flowing, the music is loud, and by the end of the night everyone is fist-bumping each other. Somehow your wife ends up on stage and is belting out an Allman Brothers Band classic, and as the night goes on the playlist gets heavier. You leave thinking that is the best damn time I've had in a very long time.
Give me Wilson all day, every day. It's the only one of the four that put a huge smile on my face.