It would have been interesting to compare the quality of the respective compiler's PGO/LTO optimizations (particularly PGO given that for GCC and ICC code is sometimes up to 20% faster with that optimization) but not interesting enough for us to purchase a Visual Studio licence.
And yes we use floating point math in most of our code, and if MSC doesn't vectorize then that would certainly explain worse performance. However this further denies the blanket statement of 'VC++ generates significantly better code than GCC.' which I was responding to.
PGO on the other hand seems very unlikely to fail due to memory constraints, atleast I've never come across that happening, the resulting code for the profiling stage will of course be bigger since it contains profiling code but I doubt the compilation stage requires alot more memory even though it examines the generated profiling data when optimizing the final binary.
It seems weird that PGO would not work with Chromium given that it's used in Firefox (which is not exactly a small project) to give a very noticeable speed boost (remember the 'Firefox runs faster with windows Firefox binary under wine than the native Linux binary debacle'? That was back when linux Firefox builds didn't use PGO while the windows builds did.)
Also, if you were doing anything heavily floating-point, MSC 2010 would be a bad choice because it doesn't vectorize. Even internally at Microsoft, we were using ICC for building some math stuff. The next release of MSC fixes this.