Hi Lady G,
I switched your post to a new topic of it’s own so your questions don’t get mixed in with other member’s posts in a more general topic.
Unfortunately you won’t be able to find a specific answer to your questions because the first rule of choosing a mattress is that 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 for anyone to be able to predict or make a specific suggestion or recommendation about which mattress 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 personal testing or sleeping experience (see mattress firmness/comfort levels in post #2 here).
There are certainly many manufacturers and retailers that can provide you with good guidance but their guidance is based on “averages” and not everyone fits inside the averages.
It’s very unlikely that the plywood was the cause of your pain since both the plywood and the slats wouldn’t have any flex under your mattress so there would be little practical difference between them in terms of how your mattress will feel and perform.
I’m not sure how you came to believe that a mattress that doesn’t have a separate comfort layer would be the cause of your back pain because this wouldn’t be accurate either. If the mattress was a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) for several years then this would indicate that the mattress was a suitable choice when you purchased it and not all mattresses either have or need a separate comfort layer if a single layer keeps you in good alignment and relieves pressure in all your sleeping positions (see post #2 here).
There is more detailed information about the most common symptoms that people may experience when they sleep on a mattress and the most likely (although not the only) reasons for them in post #2 here.
There is also more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel”.
These posts are the “tools” that can help with the analysis, detective work, or trial and error that may be necessary to help you learn your body’s language and “translate” what your body is trying to tell you so you can make the types of changes that have the best chance of reducing or eliminating any “symptoms” you are experiencing. The most common reason for lower back pain is a mattress that is too soft and the most common reason for hip pain is a mattress that is too firm (although a mattress that is too soft can also lead to hip pain if you are sleeping with your hips out of their neutral range of extension) but I would always keep in mind that these are not the only reasons for the symptoms you may be experiencing.
A topper can certainly help with a mattress that is too firm and needs some additional softness or pressure relief but a topper isn’t generally the most effective solution for a mattress that is too soft for you. While there is no way for me to know for certain whether your mattress is too firm or too soft … if your mattress is too soft or has developed some soft spots or “virtual” impressions then there are some suggestions in post #4 here that may be worth trying to see if they have any effect on your “symptoms”.
Either or both of these may be true but the only way to know for certain whether any mattress will be a good “match” for both of you will be based on your own personal testing or sleeping experience. A suitable zoning system can certainly be helpful if someone has a more challenging body type or circumstances in trying to find a suitable mattress. There is more about zoning in post #11 here and the posts it links to but whether any specific zoning system will help any particular person always depends on the body type and sleeping style of the person themselves, the mattress design, and the specifics of the zoning system.
Higher body weights can sometimes also benefit from a thicker mattress as well relative to those that are in lower weight ranges but this also isn’t always the case because there are many other variables involved besides just thickness that is part of what makes one mattress suitable for one person and not for others. There is more about mattress thickness in post #2 here and in post #14 here but I would focus more on whether a mattress is a good match for you in terms of PPP than I would on the thickness of the mattress alone because there are so many variables involved outside of thickness alone that can make a significant difference in which mattress is the best choice for you. Based on “averages” most people don’t “need” more than about 8" to 9" of latex unless they are in much higher weight ranges (closer to the upper 200’s or higher) but they still may prefer it depending on the specifics of the mattress and their body type, sleeping style, and individual preferences.
Based on “:averages” a medium comfort layer would probably be “in the range” that would tend to be more suitable for your husband but again this will also depend to some degree on the overall design of the mattress and how all the layers interact because every layer of a mattress will have some effect on all the other layers both above and below it so there isn’t a “formula” that can predict whether any specific mattress will be a good “match” for any particular person that is completely reliable or certain.
Both of the companies you are considering are members of the site which means that I think highly of them and I believe they both compete well with the best in the industry in terms of their quality, value, service, and transparency but again I don’t make specific recommendations for either a specific mattress or manufacturer because of all the unknowns and variables involved.
What you are really dealing with is how to manage the “risk” of an online purchase and there is more information in post #2 here about the different ways to choose a mattress (either locally or online) that is the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for that are involved in each of them.
When you can’t test a mattress in person then the most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart (which both of them do) and who can help “talk you through” the specifics of their mattresses and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked that they are familiar with, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs to different body types, sleeping positions, and preferences than anyone else (including me).
There is more information in the first part of post #2 here about some of the different ways that can help accommodate a couple that have different needs and preferences. Split layering can certainly help to some degree with motion transfer and it can also help in situations where each of your needs and preferences are different from each other and there are many couples in situations such as yours that are very happy they chose a split layer mattress. There is more about the pros and cons of split layering in post #2 here.
When you are down to finalists that are all choices between “good and good” (which you are) and none of them have any weak links or lower quality materials in their design (which they don’t) and if there are no clear winners between them then you are in the fortunate position that either of them would likely be a suitable choice and post #2 here can help you make a final choice based on your local testing or mattresses you have slept well on, your more detailed conversations with each of them, your confidence about the suitability of each one, their prices, the options you have after a purchase to change the firmness or exchange or return the mattress, any additional extras that are part of each purchase, and on “informed best judgement” based on all the other objective, subjective, and intangible parts of your personal value equation that are most important to you.
Again I would always keep in mind that there are no specific answers to your questions and that the only way to know for certain whether any mattress will be a good match for you will be based on your personal experience rather than “theory at a distance”.
Phoenix