Hello. I know Kingsdown mattresses are notorious for sagging after some time. I am wondering if anyone has experience with the Dylan or Demsey models specifically? I feel in love with this bed at the store, but am worried about the sagging issue. I can find lots online about other models, but haven’t seen anyone talk about these ones. Thanks so much!
Hi colleensearching,
Welcome to the Mattress Forum! 
The best way for you to evaluate how certain componentry might perform in “real world” use would be to find out information listed here so you can compare the quality of the materials and components to the durability guidelines here to make sure there are no lower quality materials or weak links in any mattress you might consider that would detract from the useful life of a mattress. If you’re able to find out this information (which unfortunately is unlikely with a Kingsdown mattress) I’ll be happy to do my best to analyze it for you. But because of this general lack of transparency, I would include Kingsdown in the “major manufacturers” group that I would completely avoid (along with any mattress where you aren’t able to find out what is inside it). They don’t disclose the materials in their mattresses and they are not very good quality/value. I would tend to avoid the Kingsdown unless there was a compelling reason to do otherwise.
While I can’t help with “what” to choose, I certainly can provide assistance with the “how”. The first place to start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones. Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of “comfort”, firmness, and PPP that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for, and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists based on all the parts of your personal value equation that are most important to you (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
Phoenix