Hi knlmwq,
Unfortunately I don’t know of any specific comparisons of the airflow of all or even some the specific types of memory foam on the market. This would be one of the most important specs of how cool a memory foam material was in actual use but it is just not generally available just like it is also next to impossible to find out the percentage of gel in various types of gel memory foams.
In addition to this … if you had a “cool” and breathable memory foam that was in a cover that was less breathable or that was softer and allowed you to sink in more or even with a different mattress protector or sheets it could sleep warmer than a less breathable memory foam with a more breathable cover and quilting materials or a more breathable protector or cooler sheets. The sleeping temperature of a mattress in other words depends on many factors, not just the foam.
My comments were based on some lengthy conversations with foam chemists and manufacturers, mattress manufacturers, retailers, and consumer feedback which clearly indicates that much (but not all) of the information about gel foams are exaggerated in terms of their effect on temperature and that I wouldn’t automatically assume that just because a memory foam has gel in it that it’s cooler than regular memory foams that use other technologies to improve the tendency of memory foam to sleep warmer. You can see some of the ways that can be used to cool down memory foam in post #6 here. As in so many other cases when it comes to mattresses … the knowledge and experience of people you deal with, and their willingness to provide you with unbiased and accurate information vs just marketing information, can often be more helpful than trying to track down some of the less common foam specs that are usually very difficult to find and only part of a larger picture when it comes to sleeping temperatures.
It’s the sleeping temperature of your complete sleeping system that is most important.
Phoenix