I've had others staying in our guest bedroom love it too and go out and buy one. At this point, with a number of moves and growing family, I've bought something like 5-6 of them.
I think Costco sells the same mattress under Novaflex or a similar name but at a slightly higher price point (the Amazon price varies quite a bit on the Sleep Innovations mattresses -- check CamelCamelCamel on it if curious).
I've moved a lot in the past few years, and each time buy a new mattress. Each time I've bought on Amazon, and to be honest, never had one I hated. Brooklyn Bedding, Zinus, etc. My favorite so far I took a complete gamble on and didn't expect much, but wow was I impressed. I have only had it 6 months so can't speak to its longetivity, but I sleep like a baby. It's a 'Revel' brand, here https://www.amazon.com/gp/aw/d/B07CZWQ97P/
My kid sleeps on one, while I sleep on a Casper, so I can compare side by side. They're more or less the same thing for all intents and purposes, except Zinus is 1/4th the price.