Hi scttz90,
Personally I would exchange it for several reasons because if anything it could easily get worse.
Larger size mattresses can sometimes be softer than smaller sizes because of an “edge effect” meaning there is more material to “pull in” from the areas beside where you are sleeping which means the mattress can have more “give”. In addition to this the Prodigy has over 6" of softer material over the support core and much of it is softer memory foam which can sink in more over the course of the night than materials such as latex because of a viscoelastic property called “creep” (meaning the foam relaxes with constant pressure over time). This means you could start off in alignment but end up out of alignment during the night or in the morning. Finally memory foam will go through an initial softening period over the first few weeks before it softens more gradually meaning the problem of sinking in too far with your heavier parts (and the poor alignment that goes with it) is not likely to go away. As you can see from my analysis of the iComfort lineup here … the Prodigy would be a “risky” construction for many people.
I would be looking at a mattress with either thinner comfort layers on top or at least one that uses thinner layers of memory foam in combination with other more “supportive” materials.
Phoenix