Hi rico,
I had quite a few criteria and many options in terms of where I purchased but in the end they offered a mattress ticking that had quiltable latex and a type of down alternative quilting that I wanted to experiment with. The value was good (even with shipping added) but this was also the case with many others and the final “piece” that made me go in that direction was the ticking/quilting combination that I wanted to try. Having said all that … the quilting on my mattress has also compressed and this may also be what has happened with yours (although in my case it was expected because I knew that this type of quilting will do that over time).
To avoid this (at least in a latex mattress) you would need a different type of stretch knit cover on the mattress that wasn’t quilted with thicker layers of fibers that are prone to compressing over time. If this (or something else) was an issue I would talk with Peter to see what he suggests.
If your mattress was using latex foam then the foam is likely still fine although the upper layers may have softened somewhat over 6 years. If the mattress uses any non latex foam … then it may have softened more and could also be part of the issue. How long a mattress lasts depends on the materials that are used, the layering of the mattress, and the “weak link” in the mattress along with how it interacts with the people who sleep on it. There’s more about the many factors that affect the durability of a mattress in post #2 here. Because of all the variables involved in both the mattress construction and the people sleeping on it … a mattress that may only last a few years for one person or couple before one or both feels it is no longer suitable for them may be perfectly suitable for a dozen years or more for another.
Before you consider Essentia … I would read this thread along with this thread (where they answered a few questions on the forum but then disappeared when the questions became tougher and a little more direct).
Phoenix