I'm sure others here have far, far more experience with QT that I do, I wanted to give my 2 cents: QT has been great for the experimental control software we run to perform experiments in our lab (https://github.com/LISE-B26/PyLabControl --- note, the readme is unfortunately out of date, but it should be ready in a week or two). I tried a good number of other GUI libraries for python, but pyQT just worked far more quickly.