Hi re-vogel,
Restava is one of the members here which means that I think highly of them and I believe they compete well with the best in the industry. If you talk to them on the phone (and I would never buy an online mattress based only on the information on any website) you will find they are completely transparent about all of the materials in their mattresses and will answer any of the questions you may have. There are no “weak links” or low quality materials in any of their mattresses and the owners of Restava have some deep roots and long term manufacturing experience in the industry. NOTE: They are no longer a member here since a redesign of their mattresses and they may no longer be fully transparent about the materials in their mattresses … see this topic.
Warranties are mostly about marketing (which in one way or another is necessary for any online business) and have little to nothing to do with the useful life of a mattress. They only cover defects in the materials or construction not the loss of comfort or support which is the reason most people will need to replace their mattress. There is more about warranties in post #174 here but if there is a manufacturing or material defect in your mattress it will generally show up very early in the life of a mattress and the length of a warranty has little to nothing to do with how long a mattress will maintain its comfort or support relative to each person. Knowing the quality/density of the foams in a mattress will tell you much more about the useful life of a mattress than the length of any warranty in the industry.
Outside of any unintentional mistake … the information they provide you on the phone will be accurate and reliable.
You have many good online memory foam options (there is a link in the tutorial to many of the better online memory foam choices I’m aware of) and IMO Restava is certainly one of them that would be well worth considering as one of your final choices and outside of their two bottom end mattresses, and like some of the other retailers/manufacturers listed there (including Novosbed), they also have the “insurance” of a very good trial period and return policy that even pays for return shipping.
Phoenix