Source: http://www.engadget.com/2013/08/02/asus-pq321-4k-monitor-gets-reviewed/
Let's be honest: almost no one expected one of the world's first 4K monitors to be ho hum. After all, it has eleventy gazillion pixels. Er, a native 3,840 x 2,160 resolution, but close enough. The gurus over at HotHardware were able to take the 31.5-inch PQ321 for a spin, and predictably, they loved what they saw. Outside of being duly impressed with how the panel handled everything from Photoshop work to gaming, they were also taken aback by the monitor's svelte frame. In fact, they found it a little tough to look back on a 1080p screen after a couple of weeks with this thing -- it's like the SD-to-HD revolution all over again. That said, they did confess that the product feels a bit ahead of its time, and the monstrous $3,500 price tag is certainly indicative of that. Feel free to hit the source link for the full spiel, but the long and short of it is this: if you're in the one percent, buy it.
Source: HotHardware