Hi devidi,
Welcome to you as well 
I’m also looking forward to finding out what you end up deciding and of course to any comments or questions you may have along the way.
As you mentioned a good return policy can certainly be an important part of the “value” of an online purchase. There is more about the different ways to choose a mattress (either locally or online) that is the most suitable “match” for your specific needs and preferences and how to identify and minimize the risks of making a choice that doesn’t turn out as well as you hoped for that are involved in each of them in post #2 here.
Phoenix