RE: xps 12 dual monitor
Unfortunately after many hours with Dell on the phone I reached the right person and the answer is NO.
1. The card output is not capable to run external monitors bigger than HDMI which is 1920x1080.
2. It runs OK with HDMI cable or through the docking station and DVI
3. You cannot run different displays but one for both (extended) not very convenient - one is 13 inch the other is 24 in my case.
Hope this helps.