Human: What are some of the most important features of a good mattress? Assistant: 
Some of the most important features of a good mattress include comfort, support, durability, and breathability. A comfortable mattress should provide adequate cushioning and contouring to your body while providing enough support for proper spinal alignment. It should also be durable enough to last through several years of use without losing its shape or sagging too much in the middle. Finally, it should allow air to circulate freely throughout the mattress so that you can stay cool and comfortable during sleep.