It's not really flamebaity, Qt is very difficult to compile/build for Windows platform, has many non-standard tools and code, looks like crap compared to officially approved GUI technologies for Windows and seems to have compatibility issues with Windows 7 and above.
I have built the commercial and OpenSource version of Qt using MSVC and MinGW. I have even built and successfully linked Qt statically using the static runtime even though that's not officially supported. It's not the simplest of builds but far from the worst I have seen and much simpler than some I had to deal with.
One part of my day job is looking after a Qt-based application. I have not experienced any compatibility issues with either Windows 7 or Windows 8 so far. Maybe in the more arcane corners, but all the normal stuff works without issues.
The only 'non-standard' tool you usually have to deal with is the moc'er. Especially using CMake it integrates into the build process absolutely seamlessly. I don't see much chance for problems down the future either: the C++ standard committee seems extremely reluctant to add anything to the language that breaks existing code, so the worst thing you might have to deal with is that you cannot use some C++XY constructs in your headers you need to moc. And even that is doubtful because parsing the moc'er does is rather lazy and accepts a lot of things that are obviously not valid C++.
While the look of Qt4 is nothing to write home about I haven't really found anyone complaining about it either, unless of course you force a non-native look on it. Qt5 is on a completely different page but I don't have enough experience there yet to comment about it.
