I echo Jim Austin’s impression on these from his assessment.. at
https://www.stereophile.com/content/focal-naim-isoacoustics-and-damnedest-audio-demo-ive-ever-experienced
“The soundstage flattened—in the sense of becoming less center-filled and curved around to the sides. Now it extended straight out beyond the edges of the speakers. When I say it flattened, I do not mean that soundstage depth collapsed. It didn't. Instead I mean that the sonic canvas, which previously had been a bit loose, suddenly stretched tight.
...The effect on the soundstage, described above, is, I think, a matter of taste. You might prefer the greater concentration of the image toward the center, as presented by the speakers with spikes...“
With the Gaia II, I sacrificed a greater concentration of center imaging (which I prefer) with a diffuser extension of the soundstage that I guess many may call that an improvement.
I will give it a week or two to see if anything changes to my liking before deciding to keep or return them.
I’ve already spent thousands on cables and quite happy with my system and these Gaia were supposed to be a game changer, but so far I think it comes down to matter of taste, and I suppose if it is to one’s liking, then they are an improvement but so far not for me.