This mattress lives up to its reviews.  We ordered the superking size from Wayfair.  It is worth every penny of its £579.  As others have reported, the mattress manages to be both supportive and relatively firm and also incredibly comfy due to the gel topper which means it feels soft and pillowy on top.  I would thoroughly recommend it as a side sleeper who often turns during the night.  Ive suffered from aches and pains at night and cant bear uncomfortable mattresses.  My normal preference is for firm pocket sprung mattresses, and this suits me to a tee.  My BF is also impressed.  Best money weve spent all year.  It makes going to bed an absolute pleasure, and I sigh in surprise every time I lie down on it.  Only downside is that ours arrived with a hole in the upholstery, but I believe that may have been due to the fact it was delivered to the wrong address and opened, possibly damaged in the process.