The mattress thing used to drive me nuts. We have been through them all, high end, low end, memory foam, you name it, we have been on this earth a while now (gulp).
My wife likes things cushy and soft, me? If too soft I get a back ache for an otherwise healthy back, yet, sometimes if out landscaping in the yard all day or digging up and planting trees my back can get stressed and if so I turn up the mattress even more hard.
I would HIGHLY recommend anyone to check these out. It's the holy grail for us, wife sets her side, I set mine.
It doesnt get more simple, there is nothing to ever sag since the guts are just a giant air bellow.
It's been about five years now, just love it, no issues, they are worth the money, to us anyway.
https://www.innomax.com/product/dual-digital-princeton-low-profile-tight-top-air-bed/
They also have more expensive models link below, I bought the above link simply because I did not want built in "plush" as the plush part can "compress" over time even with the air below it. Thats my theory. If one gets the above mattress they could always add their own mattress topper and customize it, then in a few years if it gets old just replace the topper.
For those others they also have these =
https://www.innomax.com/product-cat...on/premium-digital-air-beds/digital-air-beds/
Of course Sleep Number also makes them, heck the factory is right near us. At the time roughly 5 years ago, we actually had one ordered and then cancelled, didnt like their return policy ect. I also think and I can be completely wrong that the Sleep Number is a less robust product plus they charge extra for remote controls ect. As they want you to use your cell phone and an app. Heck with that. I prefer two dedicated remotes, not going to open an app on my phone when I want to adjust my bed.
With that said Sleep Number is a well known brand and I am sure it works well for many people.
If one thinks about it, how can you go wrong with either brand? Nothing to sag, two people get to chose how firm their side is simple stuff.