Rich Geldreich, the guy from Valve working on their Linux OpenGL debugger uses Qt Creator and looks really satisfied:

I've been using QtCreator full-time now for 6 months and I think it's awesome. I would buy it in a heartbeat, but it's a free download and it's even open source.

A bit of the background behind my need for a VS alternative: For more than a decade I've been using Visual Studio (since VC5 I think), and various other IDE's from Borland/Watcom/MS before that. [...]

http://richg42.blogspot.fr/2013/10/a-shout-out-to-qtcreator-...

Considering how VS is for games developers the gold standard by which all C++ IDEs are measured, this speaks a lot.

In my opinion, QTCreator is the one to beat at the moment. Its fast, simple and covers most of the IDE features for C++.