Hi Jill71rdh.
Your assessment is correct that the pain you are experiencing is mainly due to sinking through and reaching the coils. Quantum ® Edge Steel Perimeter in the Ultimate hybrid is zoned with 14 g coils for the top and bottom sides of the spring unit and with 17 g coils in the center third. The lower the gauge number the thicker the wire and the firmer the coil. Even though the coils in the center third of your spring unit are 17 gauge because they have a narrower diameter it acts firmer than a 14 g zone of the larger diameter coils. The people in the industry I’ve talked to approximate that the 17g narrower diameter would be roughly the equivalent of a 13.5 g of conventional diameter coils which will be firmer. At your 20.5 BMI, the higher coil firmness under your hips, combined with the plush comfort layer (20-24 ILD) and with your side sleeping is most likely resulting in the hip area pressure points and pains you are experiencing. When sleeping on your side you will exert the same force on a smaller area, which means that you will exert greater pressure, therefore, sinking deeper and bottoming out on the firmer coils below. (Think of the difference in footprint depth when wearing sandals vs shoes with high hills) This is why you do not have pains when sleeping on your back.
There is more about the many variables that can affect the sleeping temperature of a mattress or sleeping system in post #2 here that can help you choose the types of materials and components that are most likely to keep you in a comfortable temperature range. In very general terms … the materials, layers, and components of a sleeping system that are closer to your skin will have a bigger effect on airflow, moisture transport, and temperature regulation than materials, layers, and components that are further away from your skin and softer mattresses or foam toppers will tend to be more “insulating” and for some people can sleep warmer than firmer versions of the same material.
If you choose one of the types that have a thin membrane which is waterproof but allows water vapor to go through … it will be less breathable and can add to the sleeping temperature of the mattress because it can’t disperse the water vapor as easily as a wool or stretch knit cotton protector and can “negate” some of the effect of the layers below it and add to the insulation effect instead of the ventilation effect. People choose these because they are thin and can have less effect on the feel of the mattress and can have a high level of protection against liquid spills but the tradeoff is that they can raise the temperature. Those who want water resistance (not waterproof) but a more breathable mattress protector that is much more temperature controlling and effective for all but the worst spills would choose wool and then others who want something more breathable yet that has little effect on the feel of the mattress but that only absorbs moisture (from normal sleeping) but may not provide great protection against accidents (unless you remove them quickly) and doesn’t “resist” liquids would choose cotton.
The smell intensity (if any percieved) is more subject to the individual’s sensitivity to odors, and it varies by how much the latex has been aired out; Odor fades out to the point that it is not noticeable. There is more about the smell of latex in post #2 here bu,t in most cases it is reduced to levels below what people will notice in a few days to a few weeks but this can also depend on how acute your sense of smell is and on how sensitive you are to a particular smell. There is also more about the odor of new materials in post #3 here that may be helpful.
In terms of quality … blended and natural latex are equivalent, the cell structure is the same and even the firmness difference is not meaningful for the same ILD ratings … the blended Talalay is most often used because it can create a more durable foam … especially in the softer versions or ILD’s. Talalay that uses 100% natural rubber is also available and is more elastic than a blend but may not be as durable as the blend in softer versions (lower ILD’s). There is more about 100% natural and blended Talalay in post #2 here. Your own experience and preferences are always the most important factor in choosing between them. I’d run everything by your personal value equation and what is most important to you.
Phoenix