Hi docbooks,
If you’ve not already done so, you probably want to start by reading the introduction to selecting the best mattress for yourself. It covers a number of aspects about how to evaluate if a mattress is suitable for you, and to evaluate the quality/ durability of the materials inside.
https://forum.mattressunderground.com/t/how-to-look-for-and-find-the-best-mattress-for-you-read-first
Often, the larger mattress brands, like Simmons, don’t tell you what’s inside the mattress and therefore you cannot make an especially useful evaluation of the quality / durability of those mattresses. Typically, they also use lower quality materials which are less durable, often in the comfort/ top layers.
Generally, the advice here will be to steer away from Simmons.