Hi dlireland,
Celsion is the old name for what is now called Talalay GL fast response by the manufacturer Latex International. It is also used in the Pure Latex Bliss mattresses and they now call it “Active Fusion” fast response. It contains a phase change gel that is added as microcapsules in the latex to add to the natural temperature regulating ability of Talalay latex.
Phase change materials are one of the three main cooling technologies that are used in mattresses which you can read more about at the end of post #4 here.
While Celsion (Talalay GL fast response) is effective as a layer (and Talalay latex is already among the most breathable types of foam) … the temperature regulation of a whole mattress (as opposed to a single layer) will depend on a combination of many factors including how deeply you sink into the mattress, how closely the material rises up and conforms to your body, the breathability of the layers in your mattress, the type of material used, the ticking and quilting of the mattress, the type of mattress protector you use, and the type of sheets and bedding you use, and of course on the person themselves and environmental conditions. All of these have a cumulative effect. You can read more about the factors that can affect the sleeping temperature of a mattress in post #2 here.
In other words … it can be one piece of the puzzle but its cooling effects (or in this case temperature regulating effects because it affects temperature in both directionis) can be either enhanced or diminished by the other layers and components of the mattress or bedding you use and by your choice of softness/firmness.
Talalay latex has a kind of “sweet” smell when it is new that some people have likened to vanilla and other to “sugar cookies” and all types of Talalay latex are Oeko-Tex standard 100 class 1 certified (safe for close contact with babies) for harmful ingredients and offgassing.
Memory foam and latex are about as different as two materials can be so one can’t really be translated into another. The “feel” and firmness of the Genius comes more from the very firm polyfoam layer underneath the gel memory foam than it does from the gel memory foam on top so I would use your personal testing on latex mattresses as a better reference point than the “feel” of a memory foam mattress where the layering uses completely different materials and firmness levels.
Online manufacturers can act as a great “value reference” for a local purchase as long as you are comparing apples to apples. I have often suggested that a “premium” in the range of 20% for a local mattress that is similar may be a good guideline in terms of comparable value because a local purchase is less risky (you can test the specific mattress you are buying for PPP (Pressure relief, Posture and alignment, and Personal preferences) and you also have the value of local “real time” guidance (if the retailer is a good one like Healthy Back) but of course the actual number where it is worth considering an online purchase vs. a local purchase would depend on each person’s “value equation”.
Phoenix