Hi gibson,
That will depend on many factors as which you can read about in post #4 here and the posts it connects to.
One of the good things about some of the big box stores is often their return policy. The Sears return policy though needs some careful reading. You have 3 days to return their toppers for a refund but ONLY if you don’t open the packaging and sleep on it. Once it is opened you can’t return it at all. The 30 - 90 day return policy applies to exchanges only.
The topper is also 32 ILD Dunlop which many people would find to be on the firm side.
Both would be very durable materials. As the previous posts also indicated … it would also depend on some of the other durability factors involved. While it’s not possible to know how long lasting any specific combination would be for a particular person in terms of years … in relative terms and if all the other durability factors are “equal” then the latex would likely be more durable.
The Vancouver list has the best places I know of that I would include in my research. Post #21 here has some of the online options I know of that are available in Canada.
Phoenix