Hi vram,
Thanks for the kind comments … and for the donation … I appreciate both of them 
According to the Sleeptek site the Euro 4 has two 4" layers and the top layer is 2". Like all of these mattresses the layers can be customized in different ways for firmness/softness.
There is certainly no doubt that both of these use high quality materials. You can read a little more in post #2 here about the reasoning behind the separate covers for each layer. For the most part it won’t make any significant difference vs layers that aren’t covered but is certainly helpful for handling the layers and for appearance. Covered layers are probably less common or less “standard” than bare latex layers inside a mattress. Most mattresses where the layers can be re-arranged or exchanged and have zip covers would have loose layers while mattresses that have “finished” covers are more often glued together (post #15 here has more about glued vs unglued layers.)
The idea behind individual customized layering is that you can customize both the support of the mattress that comes from the deeper layers and the comfort or pressure relief of the mattress that comes from the upper layers. Two 2" layers will only be slightly softer if the ILD’s are the same as the single 4" layer but having two 2" layers can customize the “feel” of the mattress in more ways than a single layer because you can choose different ILD’s or firmness levels for each layer while a single layer only has a single ILD. For some people the difference between two 2" layers and a single 4" layer of the same ILD wouldn’t be enough to notice. The idea in both of these mattresses is to be able to choose the ILD or firmness of each layer that can be customized so that each person can customize the mattress in the way that provides the best possible PPP (Posture and alignment, Pressure relief, and Personal preferences) or their body type and sleeping positions.
These are all very high quality mattresses and use great materials (100% natural Dunlop and significant amounts of wool) but they are also in the premium end of the price range compared to other mattresses that use similar materials so they would be of more interest for people where price wasn’t one of the most significant parts of their personal value equation because there are other similar mattresses that sell for significantly less.
There are many parts to the “value” of a mattress purchase and each person’s personal value equation.
One of these of course and one of the most important is how well the mattress matches your needs and preferences in terms of PPP. This of course is very individual and a mattress that would otherwise be lower value (higher priced) based on the materials or other ways of assessing value may be well worth a premium price for some people if for some reason it was significantly and clearly “better” than any other choice they had. The ability to customize a mattress can be an important part of this but these are not the only mattresses available that can be customized and in some cases a mattress in its “standard” design and can’t be customized may work just as well if it happens to be the “perfect” design for you. There may also be real value in the ability to customize each side of the mattress for a couple that has different needs and preferences.
A second part of “value” is the type and quality of materials vs cost or the “material value” of the mattress compared to others that are similar. There are other mattresses that use the same type, quality, and amount of materials that are in lower price ranges. These may be similar but not the same (just like these three are similar but not the same). I would also keep in mind though that both of these use significant amounts of wool and have good quality covers which is a significant part of the cost of a mattress because it’s often too easy to look at the type or amount of latex alone without regard to anything else.
Of course there are also all the other objective, subjective, and intangible of the “value” of a mattress purchase that are more or less important to each person that may also be important.
As far as any others worth considering I would base that on your preliminary phone calls with each of them, on which ones you are most attracted to for the reasons that are most important to you, and on which ones are closer to you. All of them would certainly be better options than most of the other mattress stores in the city.
I would visit the others that you are considering and narrow down your choices to the “best” at each one (as if you had to choose one mattress at that retailer or manufacturer) and then make your final choice between the finalists at each one. This way all of your final choices will be between “good and good” and no matter what you choose you will end up with a higher quality and value mattress than anything you would likely have purchased from a mainstream brand or store.
Phoenix