However, once you get the basics it's quite fast and also have threads, networking, file streaming etc, so you don't need a zillion of libraries to do every little thing. Oh, and it has a great OpenGL support (see my projects at http://www.ccsoft.com.tr for screenshots)
With the help of wxFormBuilder (a free design tool), now design and modfications are very much faster.
Besides, it's been there for about 15 years. There is a decent documentation, a book, a large community to answer your questions.
My only plan is to do a project on wxPython and polish my python knowledge and see which (C++ or Python) suits me better.
The really wonderful part of the experience is that even after not programming in C++ for about 10+ years I was able to get things working pretty quickly and I'm productive with it. A lot of that is due to the wxWidgets documentation and it's well developed structure.
My only real problem is when I have to switch back and forth between Erlang and C++. Those days suck :-)