/* OT side note */
Actually, GCC's performance under windows *greatly* depends on the type of code being executed.
E.g. We (my company) uses GCC under both Linux and Windows, even though we support VC 2K5/8.
At least in our case, GCC (mingw-64) was ~10-20% faster than VC 2K5 and has far, far, far, broader features list (E.g. Very partial macro support, no in-line assembly, 'managed' version of CRT functions, etc)
Plus, can build the Windows binaries on our Linux build systems (a major plus) using Fedora's extensive MinGW support.
Per subject at hand, if you raise the warning level to the maximum (-Wall) and remove a couple of noise factors (-Wno-multichar), at least in my view, GCC tends to be far more informative than VC 2K5 - which in turn, tends to throw a lot of unused variable and deprecated use of CRT function warning, but nothing really major.