Not so easy to explain exactly what happens with words, but I made an imgur album that shows the issue. But in short, there seems to be an issue with konsole applying scaling twice when moving the window between two hidpi monitors. http://imgur.com/a/4p1nq Should I attach the images here?
Hm, this isn't a konsole issue, I see now... the same happens in other Qt applications too. Can this bug be closed?