Hi Matchmee,
Both SleepEz and Arizona Premium mattress are members of this site which means that I believe they compete well with the best in the industry.
Which one is a better or worse choice for you though depends on the parts of your personal value equation that are most important to you and on whether one mattress is a better “match” for you than another in terms of PPP. The advantage of some of the mattresses offered by SleepEz and Arizona Premium is that you can customize the mattress after a purchase by re-arranging or exchanging layers if you need to fine tune the mattress (although the one you linked from APM doesn’t have this option).
I would want to know the specifics of the foam and quilt top and the type of latex in the mattress before considering this to make sure there are no lower quality materials that could be a weak link in the mattress.
One part of “value” of course and making apples to apples comparisons depends on comparing the actual materials in a mattress and how much of each material each mattress uses (the Nutrition and a topper has 12" of latex, the SleepEz and the Arizona Premium each have 8"). Differences in the cover and the type of latex would also play a role (wool quilting is a more costly cover than a stretch knit cover for example). The Pure Latex Bliss uses blended Talalay latex from top to bottom and both SleepEz and Arizona Premium make mattresses that use the same materials and type of latex as well as other types of latex (including 100% natural Dunlop and 100% natural Talalay. The SleepEz you linked uses 100% natural Dunlop in the support core with a 2" layer of 100% natural Talalay in the comfort layer and has 3 layers that can be customized while the Arizona Premium mattress you linked uses 100% natural Talalay in both layers but can’t be customized after a purchase. All of these are high quality materials but they also have different costs and a different type of feel and performance. You can read more about the different types of latex in post #6 here and post #7 here has more about the difference in “feel” between Dunlop and Talalay. Your own testing is the best way to know which one you prefer. When you are comparing an online choice with a local mattress that you have tested in person for PPP then the risk of an online purchase and the ability to customize the mattress after a purchase may be an important part of your purchase decision if you aren’t confident that a particular design is a good match for you.
Once you are down to final choices between mattresses where there are no clear winners and where none of them have any “weak links” or low quality materials then the choice between them is really a matter of preference and which one you believe is the best match for your personal value equation.
You certainly have 3 good options to choose between 
Phoenix