Used sleep number beds for about 15 years. We had a queen for about 5 years and upgraded to a split king about 10 years ago. We're talking about upgrading again to another king with more and upgraded features.
My wife can set her firmness and I can set mine. It works out well. The sleep number saved me from a life of agony. 15 years ago I was having crippling back problems. Turned out that the mattress that we were using was 'way too firm for me but great for my wife. After switching to the sleep number the pain disappeared but the long term damage to my back had already been done. I'll never sleep on anything else. I'm a believer. It IS a helluva price to pay for what is essentially an air mattress though. It's worth it though not to be a shuffling, bent, worn out old man.