We went through several memory foam toppers at home and none lasted very long, including one from Costco. Just wouldn't buy another topper for home or RV-ing.
Six years ago we bought an 8" foam mattress with 2" memory foam layer for a previous TT and moved it into our current TT 4 years ago. It is VERY comfortable and it still looks and feels like new. We both sleep better on it than the fancy gel foam mattress we ended up getting for home. Bought it at a mattress shop while on a camping trip and shortened it on the picnic table with a bread knife.
