Hi tltb1,
There are really two ways to make a comfort choice when you are buying a mattress (see post #2 here).
The first way is with careful and objective testing of the actual mattress using the testing guidelines linked in post #1 here or in the case of an online purchase testing a local mattress that is functionally the same (see post #9 here).
If this isn’t possible because there are no suitable local mattresses with good quality and value or that an online manufacturer knows about which is functionally equivalent to their own mattresses … then the next best way is with a more extended phone call with a knowledgeable and experienced online retailer or manufacturer themselves who can provide the guidance that “on average” would work well for someone with your body type, sleeping style, and personal preferences. As long as you are inside these averages then the odds are high that you will make a suitable choice.
The third way is probably the worst which is trying to learn enough about all the different mattress specs and designs that you can make a choice based on “theory” without enough actual experience to “translate” theory into how a mattress will actually feel and perform for you when you sleep on it.
Since you are looking at local mattresses then personal testing is the best way to know whether a mattress is suitable for your needs and preferences.
The “read first post” I linked earlier links to a set of guidelines about what to look for and what to avoid and this would likely eliminate both of the Serta (because you won’t likely be able to find out what is in the mattress).
Your odds are much higher of being able to find out the details of all the layers in the Sherwood and the odds are that they are better quality/value in the same budget range.
You can test for PPP (Posture and alignment, Pressure relief, and Personal preferences) with a local mattress which will tell you whether a particular mattress is suitable for your specific needs and preferences and then the final step is to make sure you know all the details of the layers and components in the mattress so you can identify any weak links in the mattress and have reasonable confidence that the materials in the mattress won’t soften or break down too quickly so that the mattress will still be suitable for you several years down the road. You will also be able to make meaningful quality and value comparisons with other mattresses. You can’t “feel” the quality of a mattress but you can certainly identify any lower quality materials that you would want to avoid if you know the specifics of what is inside a mattress … regardless of what manufacturer’s name is on the label.
Phoenix