[DominikD]

VS is not designed for code base this size, because there aren't that many code bases this size out there. Same reason VSS ain't used for code versioning. Having said that - I don't see how having msvc build drops earlier than anyone else and testing it on the Windows code base is bad for the compiler and goes against dogfooding.

Speaking of dogfooding - using unstable builds of VS (the IDE, not the compiler which tends to be pretty stable) for something else than developing VS itself sounds like a recipe for disaster when it comes to something as massive as OS. If you read some OSS mailing lists devoted to low level dev, you'll see that what low level developers actually want is LTS compiler, not some half baked C++ year 2135 early draft compliant turd. This is why e.g. OpenBSD sticks to some old GCC with custom patches.

This and GPLv3. ;)