Had the second mattress for around 6 years now and it has completely collapsed in the middle making a comfortable nights sleep impossible.
In the process of sending photographs to Hypnia, but reading these reviews on here don't hold up much hope of a quick resolution even though it has a 10 year Warranty.
Shame as the first one bought is pristine and has no issues, clearly a manufacturing/design fault with. Only way I will have another is if it is replaced under warranty, certainly won't be purchasing another.