I was so pleased with the Isoacoustics OREAs, that I wanted to try the GAIA II footers for my speakers. Isoacoustics sells them for $299 for a set of 4 (twice that for both speakers in my case). Fortunately, I noticed them on Amazon at $259 per set so I popped. (it seems they rarely sell them for less than MSRP). Besides, Amazon offers 30 days to return at no cost.
Got them and, to be honest, I'm a bit astonished. I had been using spikes into Herbie's fat gliders, so I didn't expect a big difference. I was wrong. It was quite a noticeable difference - far more than I expected. In my room, I always felt bass was a bit too dominate. I even stuffed the rear ports of my Von Schweikert VR-35 speakers with dacron to tame it a bit (as suggested by Albert VS). With the GAIA IIs, the bass dominance changed. Bass tightened and I swear went even deeper. I took out the dacron and am loving what I'm hearing.
In addition to the change in the bass, I find that the sound stage is more open, with voices and instruments more defined in sound and space. And the top end just seems more relaxed and natural. I've still got a few weeks before I have to decide whether to return them or not, but I really can't see any chance of that happening. Not cheap by any means, but a worthy investment from my perspective. YMMV but definitely worth a try.