With all the health issues I have had over the past 15 years ReST Bed has given me a good night sleep I have not had in a long time. The reason my wife and I purchased the king size bed was you can change the firmness of your mattress to suit your preferences, which may change over time. You can have a different level of firmness on each side of the same mattress to accommodate two sleepers with very different comfort preferences. They setup the bed and showed us how to set the levels for our needs. I would highly recommend this bed to anyone with neck or back issues or would just like to get a good nights sleep.