I've ordered one but not received it yet, the reviews seem positive so I decided to go for it. It has 99% Adobe gamut, real 10 bit and as far as I can tell a hardware LUT so can be calibrated using the I1 Pro I have. Seems a very nice, very well spec'd monitor.
I had to buy a new graphics card to drive it though, it only has Display port connections and requires 2 display ports in MST config to achieve 5120 x 2880 res, I read an article suggesting around 1.5Gb video memory for each 4K monitor for non gaming use (which is me), so I figured to allow 3Gb for the 5K plus a bit more for my second monitor so chose an AMD W5100 graphics card that has 4GB memory and 10 bit.
I'm offshore at the moment so have to wait 8 days before I get to try it :/
Paul