Samsung NX500 Hands-on - 5D Mark III Killer?

With 4k video capability, a 28-megapixel BSI CMOS Sensor and a whole load of other features that you may or may not need, this Samsung NX500(http://bit.ly/SamNX500) mirrorless camera is packing a lot of stuff. Despite being a small camera, with 4k, this could potentially upstage the likes of Canon's EOS 5D Mark III(http://bit.ly/Canon5Dmk3) - just how does it perform?