I'm running a P2715Q in 1440p HiDPI (pixel doubled) mode. Works pretty well on a 15" Macbook Pro, and it looks a lot better than my old 27" 1440p screen running

I'm running a P2715Q in 1440p HiDPI (pixel doubled) mode. Works pretty well on a 15" Macbook Pro, and it looks a lot better than my old 27" 1440p screen running at native resolution. Plus, the nice thing relative to the 5K display is that it will work at 60hz with a single Displayport.