An adapter based solution is an adapter based solution.
If anything, more is dependent on the particular speaker amplifier and the synergy of the whole system than the adapter itself which alters the signal in a certain way that may be beneficial for certain things.
The trouble with tests like this is that there are far too many things done at once, which will significantly affect the perception and the point system used seems a bit stupid. I could listen to the same music on a different day and rate it differently because the sound is complex as a whole, and I pay attention to different things.
It's hard not to be judgmental, but I see a lot of confusion in these posts that might clear up, once one gathers enough knowledge by spending enough time with the sound and learns what works and what not.
Differences are there, at least to my ears, and I think saying one amp is "better/superior" than another because of this and that is a bit of an oversimplification, a less powerful Stax amp still has a different sound to aftermarket amps that might actually be advantageous regarding certain things, music types, etc. etc.
Some people have the ability to figure this out on their own. Maybe they've already had many years of hi-fi experience beforehand tweaking their speaker setups etc., others might not have the knowledge to do so (yet). Just checked, I've owned Stax for over 16 years now (at first LNS + T1S, really not bad at all for a start) and I still don't claim that I know a whole lot, it's really hard to gain first-hand experience, especially with amps.
I actually learned certain things from a 2007 post from the previous thread, it was a 717 vs an original KGSS and in some ways newer versions of the latter is a considerably more "refined/evolved" version of the same "basic" sound. Some will prefer this, some will prefer that.
The information is all there, it just takes some time to dig it up and distinguish from others (already linked it before a few times I think, so if one believes that my contribution is worthwhile, it can be found).
Actually started bookmarking a lot of posts from certain members after I tried to quickly scroll through every single page of every Stax thread just to find what I was looking for. (Yeah I know, don't ask...) I guess I should really start copying those out and make my "head-fi files" segment in case links change again, and all that work is completely lost.
But it is my "filtering" based on the opinions I agree with (and skipping ones I disagree with), so I am not sure it would be as useful to anyone.