Do mattress toppers make that much of a difference.

clarkster wrote:
How do you keep a foam topper from shifting around?..

You don't. That's why we ended up tossing out the foam topper, the old mattress, and purchased a new mattress. When we sold the camper for our current one, we kept the new mattress and put back in the original, thinking we'd put the new one in the new camper. But, our Outback came with a really good mattress (unbelievable, but true), so the "old" new one ended up in the house and we replaced a mattress in the house. Still using it.

Moral of the story... forget the topper. They ARE a PITA, and get a real mattress that's comfortable.