Hi karakuri,
“Medium firm” is a subjective term and is somewhat comparable to calling something “sweet”. What one person calls sweet may be very different from what another person calls sweet. In the same way one person’s “medium firm” may be another person’s soft and another person’s firm depending on the body type, sleeping positions, and individual preferences and perceptions of each person. It’s a relative term that varies with each individual.
The goal of every mattress is to provide good alignment and pressure relief in all your sleeping positions. Beyond these two basic needs everything else is a preference in one way or another. To have good spinal and joint alignment … the heavier parts of your body need to be “stopped” before they sink into the mattress too far which is the role of the deeper layers and what I call primary support. To have good pressure relief the pressure points in each sleeping position need to be “allowed” to sink into the mattress enough to redistribute your weight away from the pressure points which is the role of the comfort layers. The secondary role of the comfort layers is to fill in the gaps in each sleeping position (under the waist or small of the back or any of the other recessed parts of your body profile in each sleeping position) which also helps to keep the spine and joints in alignment. This is what I call secondary support. In other words alignment is the goal and good support (resistance to further compression) under the heavier parts of the body is the means.
The two mattresses you are considering are the Conform Signature and the Regalis HD. Their closest equivalent in the Tempurpedic lineup is the Contour Signature and the Rhapsody.
When you can’t test a mattress in person for PPP (Posture and alignment, Pressure relief, and Personal preferences) then the next best way to know if a mattress is the most suitable choice for you would be to test a mattress that the manufacturer has said is the closest equivalent that is available to you locally.
So my best suggestion would be to test the Tempurpedic Contour Signature and the Rhapsody as carefully and objectively as possible for PPP using the testing guidelines in post #1 here. The one that is most suitable for you and has the best combination of good alignment good pressure relief in all your sleeping positions would be the most accurate guideline possible about which of the two Select Foam mattresses would be the best choice for you. Don’t forget that testing a mattress is about testing specifically for alignment and pressure relief … not just the more subjective sense of “comfort” or “showroom feel” which may not be an accurate prediction of your long term sleeping experience.
It’s normally the best idea to get the specifics of a mattress specs from the manufacturer because they will always be the most accurate and current source of information. I agree though that their website is confusing and I believe that they recently changed from using 8 lb memory foam to 7 lb memory foam which they believe is a closer match to the Tempurpedics but they don’t seem to have changed some parts of their website to reflect this. While it’s not unusual in the industry for websites to be somewhat or partly out of date … I agree that they don’t do the best job in this area and I personally wish they would make their website a higher priority than it is. As I mentioned though … I would confirm this because they are a more accurate source of information about their own mattresses than I am.
The particles in gel foam aren’t “floating” in the memory foam but are embedded in the foam itself. The newer generations of gel memory foam have smaller particles that are embedded in the cell walls of the memory foam and are less prone to migrating out of the foam or reducing the durability of the memory foam. One of the benefits of this type of gel memory foam is that the gel particles increase the compression modulus of the foam which means it can become firmer a little faster as you sink into the foam layers more deeply and is more “supportive”. A second benefit of the gel memory foam is that it can help conduct heat away from the body to some degree either through heat conduction (with some types of gel) or through phase change (with other types of gel). In some designs the supportive properties of the gel foam would be more important and they would be used under other layers. In some designs the temporary cooling benefit of the gel may be more important and they would be used in the upper layers. It depends on which of the properties of the gel memory foam are most important in a specific mattress design. There is more about the different types and benefits of gel memory foam in post #2 here and more about the different cooling technologies and the two main types of gel (thermal conductive or phase change) and how they affect temperature in post #9 here.
They would both be different in terms of PPP but the specific differences would depend on each persons perceptions and circumstances so the best way to know the relative differences between them would be your own comparative testing on the closest approximations available to you which are the Tempurpedic Contour Signature and the Tempurpedic Rhapsody.
Phoenix