Hi Mcharv006,
Both of the mattresses you are considering use good quality materials and have no weak links in their construction so from a durability perspective they would both make great choices. As you probably know Beloit is a member of this site which means that they compete well with the best in the industry in terms of quality value and service.
Mattresses made by the same manufacturer all tend to have similar value and outside of how they feel and perform ane the main differences between them would be the cost of the materials inside them and in their construction and design.
This means that the Silhouette uses more costly and more premium and high performance materials (such as a latex core vs an innerspring and 3" of G-Flex vs 1") than the Easy Rest Classic Hybrid.
Both would make equally good quality/value choices but they will be different from each other in terms of feel and performance and which one is the best value for you would depend on which is the best match for all the criteria of your personal value equation that are most important to you.
Neither of them would be a mistake in terms of quality/durability or value and would be a better choice than the huge majority of consumers would end up purchasing in the mainstream industry 
Phoenix