Hi idlewild,
There is more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you make more meaningful comparisons between mattresses but both of these are high quality choices and neither one has any weak links in their design so which mattress is the “best value” for any particular person depends entirely on all the parts of your personal value equation that are most important to you so there is no “objective” way to decide this.
Post #4 here has more comments about how these mattresses compare that may be helpful in deciding which one is the best “match” or “best value” for you (regardless of whether it would be the best value for someone else).
Phoenix