Guarantee on Resilience range vs Origins range.

Hi, I'm looking for a new bed for myself and my wife. We are both in the 20 stone range.Currently we have a silent night ortho mattress with a memory foam topper built in. We've found this comfortable for the last six years.I've narrowed down my options to the Origins Pocket Latex 1500, seemingly because this is similar to what we have now, and The resilience 2, based on the information on your site and our weight.One of the things that I've noticed is that the warranty on the resilience range is only two years. I would have thought a mattress designed for heavier people would have afforded a longer warranty.Many thanks in advance for you help.David Owen