My only... only wish for Qt Creator (and the Qt framework as a whole) is to have a docking systems much like Visual Studio - e.g. undock a widget allows docking with another - also put some guide roses instead of moving widgets.
Qt does have a docking system, but it is nowhere near as good as visual studio's.
For the application I am building (we are using PySide, the LGPL Python bindings for Qt), I planned a fairly elaborate docking/undocking system for a collection of user-generated plots. It seems to me Qt gimped docking so it only works for toolbars on the edges of a main window. You can't "promote" a widget to be the main, central widget through the docking mechanism.
If you are fully in python, then please take a look at http://github.com/nucleic/enaml - it requires few extra modules (kiwi in C++ which is cassowary constraint system for UI widgets), and atom (python + C++):
But it has exactly what Visual Studio has, and a bit more:
I've started porting this system to C++, but gave up after realizing how much I had to do (spent a week on it, and couldn't do more).
I've chose a much simpler (again written in python) system that has some missing features (does not keep proportions, and it's not visually that appealing) - but it works in general.