Just got some more results…
64bit Vista, Intel Core 2 quad Q6600 2.4Ghz:
throw_gcc: 0 ms kernel, 4140 ms user, 5000000 exceptions
throw_vc: 16406 ms kernel, 23640 ms user, 5000000 exceptions
throw_x64: 0 ms kernel, 19421 ms user, 5000000 exceptions