Hi BackHurts,
Most latex mattresses will break in to some degree but there normally isn’t as much difference between a floor model and a new mattress as your experience seems to indicate. There are really only three possibilities that can account for your experience which are either that your testing didn’t do a good job of predicting how you would sleep on the mattress, the mattress you tested (including the support system you tested it on) is somehow different from the mattress and support system you are sleeping on at home, or that you haven’t slept on the mattress for long enough for your mattress to break in and for you to adjust to a sleeping system that is different from what you are used to. In some cases the break in period can take longer than 30 days but for most people it’s about a month or less.
If a topper on your mattress is a good “match” for you in terms of PPP then it would certainly be “worth it” IMO if there are no other reasonable options available to you but you still have the chance to exchange your mattress for a different one so it may be better to wait until you find out whether the mattress you exchange for would be more suitable for you before considering a topper.
As I mentioned in my last reply … you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components would be the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own careful testing or personal experience … hopefully using the testing guidelines in the tutorial post (see mattress firmness/comfort levels in post #2 here).
I can certainly help you to narrow down your options, help you focus on better quality/value choices that are available to you either locally or online, help you identify any lower quality materials or weak links in a mattress you may be considering, act as a fact check, answer any questions you may have along the way that I am able to help with, and help with “how” to choose but only you can decide which specific mattress is the best match for you in terms of PPP.
A mattress that sleeps warm for some people may be well inside a comfortable temperature range for others depending on where they are in the “oven to iceberg” range and on the temperature and humidity in their bedroom and the mattress protector or any mattress pad you are using, your sheets and bedding, and your bedclothes, which can all have a significant effect on sleeping temperature regardless of your mattress and in some cases changing these may be all that is necessary to keep sleeping temperatures inside the range that you are comfortable with even if one mattress tends to sleep warmer than another but there is more about the many variables that can affect sleeping temperature in post #2 here that can help you choose a choose the combination of materials and components and the types of mattresses that will have the best chance of keeping you in a temperature range that you are comfortable with.
Phoenix