It is rarely the mattress. Six things the houses in our collection changed, and the one that made the biggest difference.
Guests blame the mattress and are usually wrong. The things that decide a night are the pillow depth, the tog of the duvet against the room temperature, whether the blind actually reaches the frame, and how much noise the corridor door makes at one in the morning. Of those, the blind is the cheapest to fix and the one guests notice first.