Beauty rest mattress?

https://www.leons.ca/products/beautyrest-world-class-monarch-firm-mattress-collection?size=queen

That's the mattress I am thinking of buying. Has anyone had any experience with one of these mattresses? I've never shopped for a mattress before so I'm kind of clueless. I know I prefer firmer mattresses. And this one in the store felt firm with a bit of plush on the top which was nice. But I've come across some really mixed reviews on the brand, any opinions welcome.