Hi Suec,
You are receiving incorrect information here. You can see the Simmons warranty terms here and the warranty coverage for your replacement mattress starts from the date of your original purchase not from the date of your replacement so you won’t have any extension on the length of your warranty on your replacement mattress. In other words your replacement mattress will only be warrantied for the remainder of your original warranty.
ADMIN NOTE:Removed 404 page link | Archived Footprint: s3.amazonaws.com/simmons-media-prod/documents/Simmons_Warranty_Card_English-2.pdf
Unfortunately the specs you posted don’t contain any foam density information which is the most important information that you need to assess the quality and durability of the materials in the mattress (see this article for the information that you need to know about the quality and durability of the materials and components in a mattress). If you can’t find out the density of the foam materials I would always assume that they are low quality materials.
There is one store that does provide complete foam density information about most of their major brand mattresses (and they are the only one that I’m aware of that does) and they happen to sell the Beautyrest Black Evie as well. If you click on the “overview” link on this page you will see the quality/density of the materials in the Evie and if you compare them to the quality/durability guidelines here you will see that all of the top layers in this mattress (the top 4 3/4") are all lower quality and less durable materials than the guidelines (and some of the layers are very low quality) and would clearly be a weak link in this mattress in terms of durability which is why I would avoid it completely.
Phoenix