I travel for the majority of my career, and typically spend 100-120 nights per year in hotel for work, and maybe another 20 for pleasure. I spent about $2,000 on a mattress set in 2014, and despite it only being slept on less than 1,300 nights, has developed a dip on one side and a ridge in the middle. A rep came out to measure the sag in the mattress. The guidelines are: 1.5” dip (measured with a string across the mattress and tape measure to the lowest point, excluding the depressed areas for stitching) is what’s required for a warranty claim. My dip measured 1”, so not enough for a claim. The “ridge” is considered normal, and the only way to rid yourself of it is to sleep in the middle of the bed, according to the rep.