Hi KRTexas,
There is more about the factors that can affect the sleeping temperature of a mattress in post #2 here and about various methods that are used to “cool down” memory foam (which traditionally can sleep warmer for some people depending on the various “cooling” factors involved) in post #6 here. Their airflow channels that both allow for airflow through the memory foam and also a way to release the warmer air through the channels underneath it makes a lot of sense sense to me.
There is more information about the various gel foams (including gel memory foams) in in post #2 here and the other posts it links to (which is more like a mini course in gel foam materials) but in very general terms I would tend to compare gel memory foams to the same density of “regular” memory foams in terms of durability with the exceptions of gel memory foams that use larger particles or “chunks” of gel that can separate easily from the memory foam and can reduce durability. Newer generation gel memory foams that use particles tend to use smaller particles that will have less effect on durability. In terms of performance I believe that they are an incremental step in a good direction that along with some of the other newer memory foam technologies can help to offset some of the traditional “weaknesses” of memory foam.
In case you haven’t seen it yet (it’s one of the links in the tutorial post) and for reference as well … post #12 here has a list of some of the better online memory foam options I’m aware of and there are several of these that use various Tempurpedic mattresses as a comparison for their mattresses (or in some cases some of the other larger brands as well) so their customers can use personal testing on a local mattress to get a better sense of how their mattresses feel and perform.
Phoenix