We were just there last week and we had a brand new mattress - on day 3 - after I complained about the dips in the original mattress. The new mattress had a thicker top mattress than the one it replaced, and a lower profile box spring than the old one. It also said "Marriott" on the mattress, no other brand noted. Ours did not have a separate topper. They did not replace the bed frame. We have a memory foam bed at home and the new Marriott mattress did not feel like our memory foam mattress to me - I did notice some movement across the bed on the Marriott mattress. Our memory foam mattress at home eliminates that problem completely which is why we have one.
I was shocked at the condition of the old mattress when it was removed, and shocked that it was still in use. It looked old. When I complained, we had a new mattress within an hour which was great, but it appeared to me that they weren't replacing the mattress on a schedule, just waiting for a guest to complain. (And I am your girl when it comes to noticing a bad mattress!)