Side sleeping lessons snoring, improves circulation, side sleeping is a good way to sleep, but it does cause pressure points to be agitated and worsens wrinkles & breast sagging. We always recommend that everyone makes sure they get proper back support so check each bed for back support also. Side sleepers do best on medium to soft mattress to gently contour to your unique shape, while providing the body with the support it needs to give you proper alignment. Your hips and shoulders support most of your weight. A bed that is too hard can cause pain on hips, shoulders, knees, ankles, and elbows, and will likely cause your lower back to sag rather than maintain natural, straight alignment.
Your ideal mattress firmness is likely in the medium to soft range, and the comfort layer of the bed should be thick enough to accommodate your curves and cushion pressure zones. You should feel as if your spine is straight (in parallel to the ground) when you are lying down.
The mattress world can get confusing, sometimes it gets right down to the comfort is a combination of the support system and the layers on top. It is best to get most of the comfort from the core and contouring, because the comfort layers will flatten out over time. The more expensive beds tend to build up the core for longevitiy. This is perhaps the most simple and straightforward of selecting the best mattress and is where you choose between different mattresses that have the "feel" you like, good pressure relief, and good spinal alignment and compare them based on quality and durability.
Now Balance Out Value
As confusing as the mattress world is most people consider this part the most fun ... and sometimes the most difficult. This is where you decide on exactly what to buy based on the combination of different features and the any difference in value in buying a similar mattress from different sources and where all the objective, subjective, and intangible parts of your personal value equation become important. The difficult part can be making all the final decisions about the smaller details of your mattress and which ones you really want and which ones you don't. For example, do you want a wool quilting which is a natural fire barrier and provides good temperature regulation or would you rather have a thicker circular knit ticking which will let you sleep closer to latex or memory foam and help it relieve pressure better, in which case you may be fine with a viscose/silica fire barrier. At this step you will have a clear idea of exactly what type of mattress works best for you and the details of its construction. You may have actually found one that you would buy or a couple that were so close that you know exactly what needs to be changed to make it perfect (such as ... this one would do but it would be perfect if it was just a tiny bit softer on top).
There are so many different combinations, first I would understand the core 2" of HD polyfoam over a Bonnell innerspring and the second had 2" of latex over 6" of HD polyfoam. In comparing the two you would quickly see that the latex comfort layer is far higher quality and will last much longer than the HD polyfoam comfort layer. You would also know that the HD polyfoam in the comfort layer of the first mattress would be the weakest link and could wear out much more quickly than the same HD polyfoam material used in the support core of the second mattress since the comfort layers are more subject to stress and wearing out (a mattress will usually soften and break down from the top-down). Your choice would be simple if they were roughly the same cost or even if the second cost a little more since it is clearly a higher quality mattress and would be much more durable. This is your focus on long term satisfaction with your mattress so you won't find you are one of those who love your mattress in the store and for a few months after only to discover you made a mistake.