Hi niroth,
The only way to know whether it would work with any certainty is to test in in person. This is the only real benefit of dealing with Costco because their refund policy can reduce the risk of a purchase that you haven’t tested in person.
I think my answer here to another member about tying to compare memory foam to latex would apply to your question as well. They really are apples to oranges comparisons although both can relieve pressure very well.
The choice between them is really a personal preference but they are not comparable in terms of how they feel or perform … even with similar ILD’s.
I personally wouldn’t buy any topper unless I knew the density and I don’t see the density of the Novaform gel memory foam topper listed on the Costco site.
Phoenix