I’ve Gaias on my Magico A3’s which are on a solid 3/4" oak floor. The bass response tightened up most noticeably, and the sound stage instruments and vocals became more defined relative to one another. If you read the ads and reviews for the Isoacoustic Gaias they surprisingly accurately describe the results I got from them. I thoroughly researched the Gaias and many of their competitors. I’m still amazed they lived up to the advertising and reviews as I’m pretty cynical, and when does that ever happen?
If money was no object I might have gone with the Townsend pods but they are pretty massive looking which can be a drawback if your speakers are in a living space. I was so impressed with the Gaias, I’ve now their equivalent pods under all my components to good effect. I’m guessing you’d be pleased too. I didn’t notice any harshness added to the treble response like fpomposo noted above.