Hi patdenver,
Hopefully you’ve had the chance to read the tutorial post here which has all the basic information, steps, and guidelines you will need to make the best possible and most suitable choices … and know how to avoid the worst ones.
Outside of how suitable a mattress is for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) … a mattress is only as good as it’s construction and the quality of the materials inside it regardless of which manufacturer’s name is on the label. I would avoid any mattress that either uses “unknown” materials in their mattress (the upper layers especially which are the weak link of most mattresses) or uses lower quality materials. This would include most of the major brands that you would probably recognize including Stearns and Foster.
You can see a few comments about Sherwood in post #2 here and a forum search on Sherwood (you can just click this) will bring up more information and comments about them as well but overall they tend to build mattresses that use higher quality materials than the major brands and are more transparent as well but with any mattress purchase I would want to know the specifics of what is inside a mattress to make sure it doesn’t have any “weak links” and to make more meaningful comparisons with other mattresses.
Mattresses that use thick layers of lower quality materials in the comfort layers (the upper layers of a mattress) including pillowtops (which add additional layers of foam or fibers in a separate “pillow” on top of the mattress) or any other type of mattress will soften and break down much too quickly and this leads to the loss of comfort and support and the need to replace the mattress much sooner than most people would hope (or “tolerate” a mattress that they don’t sleep well on any longer). Foam softening and loss of comfort and support also isn’t covered by a warranty because it’s not considered to be a “defect” in the material unless there are also impressions that are deeper than the warranty exclusions which only happens in a fairly low percentage of cases (see post #174 here about warranties).
If you follow the steps in the tutorial post your odds of making a suitable and good quality/value choice will be much higher.
Phoenix