Hi Frydakis,
Welcome to the Mattress Forum! … all the way from Greece 
Post #13 here has more information about the most important parts of the value of a mattress purchase that can help you make more meaningful comparisons but it comes down to testing for suitability and PPP (Posture and alignment, Pressure relief, and Personal preferences), checking the quality of the materials for quality/durability, and then making value comparisons based on the parts of your personal value equation that are most important to you.
The first part (PPP) would be up to your own personal testing on the mattress.
For the second part which is the quality of the materials and identifying any weak links in each mattress … I can certainly help but I would need to know the information listed here about the materials inside each mattress. The foam quality guidelines that it links to are expressed in lbs/ft3 and they may be expressed in kg/m3 in Greece so there is a density conversion calculator here which can help you convert from one to the other if you need to. For example 4 lb density would be 64.1 kg / m3 (rounded), 1.5 lb density would be 24 kg / m3 (rounded).
[quote]Magniflex: Magniflex US | Online Store
is referring to Magniflex Comfort Dual 10 with padding in memoform 0,78 inch and hypoallergenic fiber, layer in Memoform 1,96 inch and Elioform 6,7 inches. (total height 9,85 inches)
Is Elioform (firm support foam) that Magniflex uses a quality material or just a another marketing term for foam ? and lastly 0,78 inch of memoform (memory foam)is it something that will probably last for the full life cycle of 12 years guarantee that the maker has provided ?[/quote]
Unfortunately they don’t provide the density of the memory foam (memofoam) or the polyfoam (eliofoam layers) so it’s not possible for me to make any comments about the quality or relative durability of the materials. If you can find out the density of the memory foam and the polyfoam and list them on the forum I’d certainly be happy to make some comments about the quality of the materials or help you identify any potential weak links in the mattress.
[quote]Dunlopillo: www.dunlopillo.gr/product-info.php?id=43#.VFDcdodH-ZY
is referring to Dunlopillo, fully made from Talaly latex, as explained in detail in the forum. total height 8,26 inches.[/quote]
Based on the description and the image … this appears to use Talalay latex from top to bottom which is a high quality and durable material and if this is the only material in this mattress (which I would confirm) then there would be no weak links in the mattress. I would want to know whether it was their blended or 100% natural Talalay for the sake of making comparisons to other latex mattresses but either way it would be a very durable material.
In the case of the Magniflex … the entire mattress is Oeko-Tex certified so I would have no concerns about the glue or any of the other materials or components in terms of safety.
In the case of the Dunlopillo … the glue they use to fabricate the latex layers themselves is a water based glue (not a solvent based glue) and the latex cores themselves are also Oeko-Tex certified so they would also be completely safe. I don’t know whether the layers themselves are glued together or the type of glue they use if they are but it’s likely that they would also be water based and be safe as well.
Phoenix