Hello. I am fond of these form-factor laptops and now using one Timeline 3810. I wanted to upgrade my external monitor to a 27-inch(2560x1440) one. I went to a store to look at one dell model with that resolution - the U2713H. I was limited to using the HDMI, I had some suspicions that it won't load the native resolution. And it couldn't - it only ran at full-hd(1920x1080). I, then, researched and it seems that HDMI implementation across OS-drivers, GPUs, cables and even the monitors themselves(providing EDID-data) may impose such limitations.
So, as I like that particular model that you reviewed, I'd like to ask you try hooking it to one extended-resolution(2560x1440) display over some good HDMI 1.4 cable. That way those of us who need to combine the cutting-edge portability with the great desktop experience that these extended-resolution monitors provide, could clear-out the options available.
Kostadin