But it's still one of the most expensive mattresses in the world ... "lavishly soft" and "opulent", and the company says it takes 10 craftsmen three days to handcraft a single Palais Royale.

Because there are a few different mattress collections available and each collection features several different mattresses, ...

I've tested all nine mattresses in Casper's current line-up, and despite my glowing Casper Nova Hybrid Mattress review, I can't recommend the brand's most expensive mattress: the Casper Wave Hybrid.

Aly Lopez is a writer on the sleep team at CNET. She tests, researches and reviews everything sleep-related, from mattresses and bedding to sleep trends and hacks to sleep technology and supplements.