That mattress that we bought last year is back in the guest room. It was too soft for me and hurt my back to sleep on it because it made everything in the middle of the mattress sink lower than anywhere else.
I slept on my old, firmer mattress last night and my back felt a lot better in the morning. So today I swapped mattresses again. The guests can have the pillowtop memory foam mattress. I'm happy with my old one. It is kind of weird though since I feel so low to the ground now since the pillowtop one was a lot thicker, but I'll get used to being this low again.