Jacobson et al. studied subjective sleep ratings of 62 persons at home for 28 nights in their own beds (pre) and for 28 nights on a new “medium-firm” bedding system (post) [91]. Unfortunately, order effects were not controlled by way of counterbalancing the two mattress conditions. They found immediate and significant improvements in all areas of physical pain, sleep comfort and sleep quality on the new bedding systems. Enck et al. evaluated questionnaires of 265 hotel guests in a double-blind study comparing three new mattresses of different price and quality with respect to the eight year old mattresses of the hotel [57].