Hi Quickstrike,
As I mentioned in an earlier reply in this topic … I would keep in mind that the length of a mattress warranty has very little to do with the durability or useful life of a mattress or more importantly how long it may be before you need to replace it. Warranties only cover defects in a mattress and not the gradual (or rapid in the case of lower quality materials) loss of comfort and support that is the main reason people will need to replace their mattress. There is more about mattress warranties in post #174 here. Warranties that are longer than about 10 years or so are usually more about marketing than anything else.
Phoenix