I bought the 12 inch king size original mattress only a week ago but so far I am super happy with my choice! I experienced a back pain from sleeping on my old matress (a cheap sprung) but since I sleep on Hypnia, the back pain is gone. It's really comfortable and the 12 inch one makes my bed very high but I love it. The other positive side I need to highlight is the price. Before I placed an order, I made an extensive research and found "the best mattresses on the market" massively overpriced (it's like you pay for two and you get one). Hypnia has a reasonable price, in fact I think you get more than what you pay for so I can only recommend this mattress.