Hi rolex,
Their mattresses haven’t changed in terms of their materials or designs since the later replies in this topic and in post #2 and the rest of this topic as well so my thoughts about them would still be the same.
They haven’t been on the market for long enough for anyone to be able to really be able to make any meaningful comments about their durability based on actual experience. I would also be very cautious about using other people’s experiences or reviews on a mattress (either positive or negative) as a reliable source of information or guidance about how suitable or how durable a mattress or any specific material may be for you and in many cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person may be completely unsuitable for someone else to sleep on either in terms of suitability or durability (see post #13 here).
Outside of PPP (Posture and alignment, Pressure relief, and Personal preferences) … a mattress is only as good as it’s construction and the quality/durability of the materials inside it regardless of the specific mattress or the name of the manufacturer that makes it and there are much more reliable ways to assess the quality/durability of a mattress or know whether it has any weak links in its design than using reviews (see this article and the quality/durability guidelines that it links to).
While there is no way to quantify how long any mattress will last for any particular person because there are too many unknowns and variables involved that are unique to each person, if a mattress is well inside a suitable comfort/support range and isn’t close to the edge of being too soft when it is new and meets the minimum quality specs that are suggested in the guidelines here then it would be reasonable to expect a useful lifetime in the range of 7 - 10 years and with higher quality and more durable materials like latex or higher density memory foam or polyfoam (in the comfort layers especially) it would likely be in the higher end of the range or even longer. There is also more about the many variables that can affect durability and the useful life of a mattress in post #4 here.
Unfortunately it’s not possible to make any meaningful comments about any mattress unless you know the type and quality of all the materials inside it so you can identify any lower quality materials or weak links in the mattress. In very general terms though I would avoid all the major brands (or any mattress where you don’t know the quality of the materials inside it) and the chain stores that often sell them because they all tend to use lower quality/density materials than I would be comfortable with in their comfort layers (see the guidelines here). Even the few that don’t have any obvious weak links in their design are generally not in a good value range compared to many other mattresses that use higher quality and more durable materials and are in lower price ranges.
Just in case you haven’t already … I would also make sure you’ve read the mattress shopping tutorial which has all the basic information, steps, and guidelines that can help you make the best possible choice … and more importantly know how and why to avoid the worst ones.
If you let me know your city or postal code I’d also be happy to let you know about any of the better options or possibilities I’m aware of in your area.
Phoenix