This is not strictly a DT tip but one for people who may be ageing and still spend hours with DT everyday.
DT works great on a 27inch display, except that as I struggle more with age and failing eyesight it just got all too small and I seemed to spend way to much time zooming and enlarging fonts. The first thing I tried was use the standard scaling options in Display preferences. While they help to enlarge everything, they also leave text and pdfs a blurry mess. What I really wanted was retina scaling like my Macbook Pro but on the external display, so that all the interface elements are scaled, but everything else stays pin sharp. It turns out that it is possible to have retina scaling on an external display with a fantastic little utility called SwitchResX - http://www.madrau.com
Now I can have my 27inch monitor at a virtual 1920x1080 resolution (or bigger), text and pdfs are sharp and reasonable sized and I can actually sit at a decent distance away and keep files and books between the monitor for reference where they are easier to use.
I hope this helps other people as much as its helped me.