So far I really like the FCPs. I went with the FCPs because of the price and that they are a 2.5" strut, which works better due to the weight of the GX460. It also doesn't help that I was able to get FCPs and TC UCAs for basically the same price as a 2.5" Icon suspension without UCAs.
I went with the B series springs which is their medium duty spring and the ride is only slightly firmer than stock. I've always been used to gas shocks and was a little skeptical of the foam ones, but they are pretty freaking awesome in terms of ride quality. Now that I got them installed, I just gotta find a weekend to do some wheeling to really test them out!