Hi Triumph3,
I wish you had found us sooner as well since it would have helped you avoid all of the choices you ended up making … but of course that didn’t happen so the best that can happen now is to make the best of a difficult situation where you really don’t have any great options available to you (unless you were somehow able to get a refund for your mattress and start all over again using a very different approach to finding a mattress).
Unfortunately you inadvertently ended up repeating your previous experience by buying a major brand mattress which has lower quality and less durable materials in the comfort layers … even though they may be firmer. These are the types of mattresses I would avoid in any firmness level (see the guidelines here).
You can also read my thoughts about buying a firmer mattress and then adding a topper afterwards in post #2 here and unless you can test the specific combination in person to make sure it’s a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) it can be a very risky approach that can be even more difficult than just finding a suitable mattress in the first place because choosing a topper that is a good match for both you and the mattress you are using it on can be a very uncertain process that involves some trial and error.
If you did choose to go in this direction then the Beautyrest world class royal palms firmBeautyrest world class royal palms firm is in a higher budget range than you would need if you are adding your own comfort layers in the form of a topper and I would probably have used a lower cost mattress as the “base” under your topper since by buying the Beautyrest world class royal palms firm you are really only buying foam layers (and lower quality at that) that you really don’t need and that can be more of a liability than a benefit. While a topper will help with the durability of the Beautyrest world class royal palms firm … it would still be a lower quality and less durable choice for a base mattress under a topper than I would normally consider.
I’m not sure how helpful this is because their 45 day comfort guarantee only applies to mattresses in the same or higher price range and there isn’t a higher priced mattress (or any mattress for that matter) that I would normally consider there and you would only be using good money to chase after bad IMO (unless they carry a mattress I don’t know about that would be a good match for you in terms of PPP without a topper and where you can find out the specifics of all the layers to confirm that it doesn’t have any weak links in the materials … see this article).
The choice of material for a topper is a personal preference so it would depend on how you like the feel and performance of latex. Latex is a very durable material and it can certainly make a good choice for a topper for those who like it but I would spend some time testing different types and firmness levels of latex in some local stores to get a better sense of whether you like the “feel” of latex and if you do which which type of latex you tend to prefer. There is more about the differences between memory foam and latex in post #2 here and there is more about the difference between the feel of Talalay and Dunlop latex in post #7 here.
I would tend to be cautious with a featherbed because it’s more of a “feel” item that is much less resilient and supportive and less pressure relieving overall than a foam topper. There is more about featherbeds or fiberbeds in post #2 here and the other posts it links to.
So overall … since you aren’t experiencing any back pains on your mattress and it appears that all you need is some additional softness and pressure relief … it seems to me that the best of some “not so good” options would be to choose a topper that is a good match for both you and your mattress so that you can add the additional softness and pressure relief that you need on your mattress. It would also have the side benefit of extending the useful life of your mattress as well so that the lower quality materials in the Beautyrest Black will soften and break down a little more slowly.
Once you have decided on the type of material that you would prefer in a topper (including testing some latex locally to see if you like how it feels in general terms) then post #2 here and the additional topper guidelines it links to can help you use your sleeping experience on your mattress to choose the type, thickness, and firmness for a topper that would have the best chance of success. It also includes a link to some of the better online topper sources I’m aware of.
You can see my thoughts about Karl and Sleeponlatex in post #4 here and post #3 here and a forum search on “sleeponlatex” will bring up more information and feedback about them as well. They are one of the sources that are included in the topper list I linked and if you like Dunlop latex then they would certainly be worth talking with.
You can read more of my thoughts about Ultimate Sleep in this topic and as you can see I would be very cautious here and would probably look elsewhere.
Phoenix