To expand on Laserlight's point, one of the primary reasons to use GCC is that it is often first to implement current/new C++ features, so keeping one's GCC toolset current is usually quite important, though sometimes the most recent versions may be more difficult to install on some platforms. These days, on Windows with Visual Studio, Clang is much easier to use than GCC, while on Linux it is often easier to keep GCC current than it is for Clang.
