I'm using a 4k 27inch widescreen monitor along a with a smaller (21 or 22 inch, can't remember which) hd monitor which I have in portrait orientation for most of the windows other than the document window. I do find some things on the document window a bit on the small side, but then I really need to go to the optician for an eye check and new glasses anyway. But my personal preference for using poser is the machine I'm typing this on which has a qhd (2k) monitor which gives me the best compromise between workspace and ease of viewing. Of course in poser 11 you can change the ui scale factor to make things more visible, I've done this on my 4k laptop, but I get lots of clipping with bits of labels missing.