Hi AlexGuardian,
Welcome to the Mattress Forum!
I’m just curious if you know the exact configuration of your Q3? Whether you went with 100% NR or blended, it is a Dunlop product. In the medium/firm configuration, it certainly can have a comfort that leans toward what most would consider the “firmer” end of the spectrum. When something happens suddenly, my first question always goes to if you experienced any changes in fitness or experienced an injury (I know you stated you are quite fit) at that nine month mark. Also, what type of a support structure do you have under your mattress?
While it’s not possible to “diagnose” mattress comfort issues on a forum with any certainty because they can be very complex and there are too many unique unknowns, variables, and complexities involved that can affect how each person sleeps on a mattress in terms of “comfort”, firmness, and PPP or any “symptoms” they experience … there is more 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 .
When you state “back pain”, was this more of a tenderness/soreness that went away a bit after waking, or did it last all day? It certainly wouldn’t be uncommon for someone who is lean and of a lower mass to have some “soreness” when sleeping on a mattress they perceived as too firm.
I’m assuming you sleep on your side (as you referenced hip pain). I usually tend to trust people’s initial self-diagnosis of their issues, so it is entirely possible your mattress was a bit too firm for your preference, and even the addition of the 2" Talalay plush topper (which would generally be a smaller increase in plushness) still didn’t provide enough relief for you.
As I mentioned previously, I’m unfortunately not able to diagnose issues online nor able to “feel what you feel”. The best I can offer would be some of the common complaints of discomfort and their causes, which I linked to earlier. Regarding using memory foam and latex on top of a firm base mattress, there certainly is no hard and fast rule about combining these products. I personally like the combination of latex on top of a layer of memory foam, as you get some of the “dense deep down” comfort of memory foam, but more breathability and buoyance with the latex on top. But that’s me, and you may actually prefer the feel that memory foam provides. I’m guessing you’re keeping your current latex topper, so you would be able to experiment not only with a single layer of memory foam on top of your current mattress, but you could also use it in combination with your current latex topper. Since you’re already familiar with the topper guidelines, if you were thinking of using memory foam alone, a 2" piece probably wouldn’t be adequate for you based upon your feedback about your latex topper, so I’d lean toward a 3" or 4" piece. Look for something that has a good exchange/return policy just in case the item doesn’t turn out as well as you had hoped. If you are considering using the memory foam with the latex topper, you may wish to stay in the 2"-3" range. Again, these are general guidelines, but hopefully they’ll help provide you a bit of guidance. And while 4 lb. memory foam might be enough for you to “get by”, I would recommend 5 lb. memory foam.
I’ll look forward to an update on your progress and other questions you might have.
Phoenix