Hi willwill,
Easy Rest makes some good quality mattresses with good value (depending on the prices at the store that is selling them) and while they are a Chinese manufacturer … they are also CertiPur certified just like most North American foams.
Regardless of the manufacturer though … it’s always important to make sure you know the details of all the layers in your mattress (the thickness and type of material in each layer) so you can make meaningful quality and value comparisons. If you call the retailer they should be able to provide this to you (either from the information they already have or with a phone call to Easy Rest) and it’s certainly not the customer’s job to have to find this out on their own.
I would also compare the cost of a mattress to other mattresses and the cost of an adjustable bed to other adjustable beds so you can make better comparisons with each one individually. The adjustable bed thread here has information that would be helpful including a few of the merchants that I use for “value comparisons” for adjustable beds.
Phoenix