Hi Restless inNJ,
I think that just about every person who buys a mattress or is a member of the forum has wrestled with a similar scenario which is all about how to choose between “good and good” choices. At this point … it’s time for me to step out of the way and I don’t think anyone can or even should tell you what to choose at this point but some guidance in how to choose may be helpful. I know it took me several weeks to narrow down my own final choices when I last purchased a mattress as I kept changing my mind about what was most important to me 
The best news is that you have eliminated all your worst choices and in terms of quality it would be difficult to make a mistake.
Every mattress purchase though includes more than just the “material value” of the mattress and all the many tradeoffs involved in the mattress itself as well as all the other options and services that are part of every mattress purchase are all part of what I call your “personal value equation”. There is also more about the most important parts of the “value” of a mattress purchase in post #13 here but in the end everyone will need to decide what is most important to them and attach a “value” to all the objective, subjective, and intangible factors that are part of any final decision. There is no “best and worst” any longer at this point … only best for YOU.
It may also be worth attaching a “premium” in the range of 20% or so (each person may choose more or less than this depending on their risk tolerance and on the return or exchange policies of the online retailer/manufacturer) to get to “equivalent value” if you are comparing local to online because of the extra risk involved in an online purchase compared to a mattress you can test in person. Once the local premium goes beyond this in an online vs local comparison then I would look more seriously at online options. If you are comparing online to online or local to local then of course this wouldn’t apply but some of the other parts of your personal value equation may still be important factors and increase or decrease the risk of a specific choice in terms of how well you believe it “matches” your specific needs and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences). In many cases, local manufacturers will also allow comfort adjustments and any exchange or return policies and how much they may increase the cost of a mattress are also part of the value of any purchase. I would also make sure you are comparing mattress only prices to mattress only prices to that your comparisons are more apples to apples.
I would also strongly suggest that you have a good conversation with each of the online choices you are considering. This can play a big role in which direction you end up choosing. Once you have looked carefully at the different options and benefits of each choice and how you feel about each … and the options you have if you make the wrong comfort choice … you will usually find that you will start “leaning” in one direction or another. I would also remember that when you look back on a mattress purchase 10 or more years from now you will remember much more about how well you slept and how long you slept well than you will about the purchase price of the mattress although I’m also not suggesting that this isn’t one of the most important parts of value and your final decision.
The bad news is that even with good or great mattresses to choose between final choices are not always easy to make … especially when it involves a combination of objective, subjective, and intangible factors that can be difficult to attach a “value” to or when the differences in “value” between them seems very small. The good news is that any of your choices are better than what the large majority of people end up purchasing and in terms of quality and value there are really no “bad choices” or “mistakes” left any more and when you are at this point and there are no clear winners between your finalists then the odds are high that any one of them would be a good choice that you would be happy with.
Phoenix