Robert, I have no experience with the GAIA. There are three models of that foot, each of which covers a pretty large weight range (GAIA III: up to 70 lbs., II: up to 120lbs, I: up to 220 lbs). Prices are $199/set of 4, $299, and $599 respectively. The Townshend Pods are closer together in range: 2-4 lbs., 4-8, 8-16, 16-32, 32-64, 64-128, iirc. Unlike the GAIA, all models are priced basically the same.
I had no intention of buying both the GAIA and the Pods, so chose between them based on my evaluation of their design. Everyone is free to do the same. All the IsoAcoustics speaker isolation products are based on the use of rubber as the means of providing that isolation. All rubber, whether the plain old stuff feet have been made out of forever, Sorbothane, Navcom, EAR Isodamp---and to that group I’m going to add the IsoAcoustic rubber---DOES provide isolation, but down to a not-very-low frequency. And it is somewhat reactive, leading to the well-known "spongy" bass that spikes eliminate.
While the GAIA may afford sq improvement in some or even many situations---and I don’t question that it does---I don’t view rubber as the optimum route to take in the endeavor to find the optimum speaker (or any other component) support. Again, everyone is free to follow the path of their own choosing. If I had the $, I’d have Herzan or Minus-K platforms until all source and electronic components. Since I don’t, I’m going with the Pods and Machina Dynamica Springs, which are replacing some of my Townshend Sinks and roller bearings. As should be obvious, I believe in true isolation, not "tuning" via resonant materials, which add their own sound to that of the source and hi-fi components. That path does not align with my personal understanding of the nature of the "problem" and how best to address it.
By the way, the rubber of the Townshend Pod is used to create a semi-sealed enclosed air space around the spring, which, used in tandem with the small air escape hole in the top of the Pod, creates a "bellows"-like design. That enclosed air DOES afford damping, so in that way the rubber used in the Pod IS involved in damping, but not at all in the manner of the rubber products named above. The full explanation and demonstration of the design is viewable on the Max Townshend You Tube videos.