Hi phllm47,
Welcome to the forum.
When it comes to legacy brand mattresses, it seems the older they are the better they were. At the time you purchased your Sealy, it may not have been merged with Tempur yet. I had purchased my Sealy Posturepedic prior to the merger, myself, it only lasted 11 years (compared to my Serta Perfect Sleeper which lived for 25 years, prior to the Sealy). Unfortunately, prioritization of corporate profit over old fashioned quality it the name of the game for many larger, international companies.
There are a few smaller companies out there that are making traditional style, one and two sided mattresses you might consider.
The DLX Premier Hybrid (my friends just replaced their 2019 S&F Cassatt- it gave out in almost 5 years - with the DLX PH) is a great option that allows you to tweak the comfort layer right from the start, or after the fact. The comfort layer can be split, for individualized comfort, or incorporate a single comfort layer to accommodate both of you, as you likely have been experiencing with your current Sealy. The cover/panel layer will offer enough cushion even with the firmer comfort layer. They also make a latex version of this mattress too. @DLX would be happy to discuss those needs further.
Engineered Sleep has the Duo series that offers a similar concept of individualized comfort for each sleeper. It is just facilitated a bit differently with the flipping of the core layer of the mattress, but does allow for changeable comfort layers as well. The folks @EngineeredSleep can even customize mattress options to taylor to specific needs.
Backscience makes some interesting and comfortable mattresses, with feels similar to the traditional legacy mattresses, but with better thought out designs, modifiable lumbar support and a heck of a trial and warranty. @BackScience Dr. Rick, a chiropractor who designed these mattresses is always happy to help pinpoint what is best for you preferences.
Some key points to consider is be certain you have a rigid, sturdy foundation. If a slatted foundation, something like this new offering from Mattress Foundations available with and without feet, is what I call the “Tank” of foundations. If you are looking for a bedframe with headboard, @EuropeanSleep bedframes are as solid as they come, solid as a rock and you can stand on these frames and they dont budge.
The foundation is an important component as part of your bedding system, and will be key as to how long your mattress will last, beyond the build of the mattress itself.
Your pillow selection is another component that will ensure you are properly aligned and get a great night’s sleep. I have written about it here.
You can certainly run out to your local macy’s, bloomingdales or furniture store and test some mattresses. It is an easy way to eliminate what is too soft. The issue will be longer term durability. Knowing the specifications of the mattress can help guide you in the right direction. One bad layer of foam, or more than 1" of lower quality foam, can cause a mattress to fail in short order. Memory foam, if you choose a mattress that incorporates it in the build, should be at the very least 3.5-5lb density. HD Polyfoams should be no less than 1.8lb, unless it is used as a base under your coils, 1.5lb would be acceptable.
When shopping for a mattress, questions about these components, should be asked and answered competently. Otherwise, you may be running into an inexperienced sales person, who may not understand your needs and preferences based on your body profile and sleep positions.
The Trusted Members here at TMU, are all seasoned experts, who see folks like you every day and can address the your personal preferences, posture & alignment, and pressure relief needs, without skipping a beat.
Hopefully this gives you a head start on your new mattress journey.
Maverick