After 18 months with our Leesa, my side seemed to be getting softer than my wife's side. It was giving me back aches in the morning.

She prefers a softer mattress so we rotated it about a year ago and it's been fine for both of us since then.

I've slept on her side a few times and it's been fine, so maybe having a lighter person on it has let it firm up a bit.