Hi Grateful,
I would be cautious with their entry level mattress unless it was “perfect” for you based on your BMI and the only reason you were choosing it was that it was the best choice for you not just because it was the lowest cost model. You can see some recent feedback about the VI Spring Elite from one of the forum members in this topic.
Post #2 here may also be worth reading about comparing a VI Spring to other mattresses and post #4 here also has a list of other innerspring/natural fiber mattresses (including some of the ultra premium brands) but these are the types of mattresses that have more complex designs that aren’t as easy to compare based on just the materials and components and you would need to test them in person to see how they compared because there is a wide range of differences in the general innerspring/natural fiber category both in terms of the type of innersprings, the fibers used, and the design and construction of the mattress.
Phoenix