Hi Rawr,
Welcome to the MattressUnderGround.
This is a question that frequently pops up. Below are a couple of recent responses involving a response to your answer.
Since you mentioned @Sleep_EZ, they are excellent at responding in more depth regarding their products.
While there is no simple answer as mattresses do require a bit of maintenance and care, and the two do go hand in hand, combined with the physical profiles of the sleepers using the mattress.
This is an excellent summary of mattress maintenance and longevity.
Mattress Longevity
@Sleep_EZ has touched on this recently as well in several responses