Not a huge deal, but after doing the qt upgrade, qtcreator's welcome menu>examples tab doesn't find any of the installed examples. I looked to see if I could see the path it was using to find the examples, but couldn't find anything. I do have qt5-doc installed which is the optional dep suggested on qtcreator to provide the examples.
It also looks like the editor does not have the correct paths setup for the #include autocompletion and finding. I'll dig around a bit more as far as specifying the Qt path.
As far as the include paths...
qtcreator specifically was having trouble finding #include <QApplication> - I found these threads detailing differences between qt4 & 5
Adding the QT += widgets allowed qtcreator to find the QApplication header