Not a lot of hard numbers in the review, but the overall tone of this Windows 2003 review isn't what I'd call postive:

I honestly don't understand what Microsoft thinks they're doing. Server 2003 is pitched at large business but without significant application server support, Server 2003 simply can't work for users or resellers. As an operating system itself, it's fine, but as the crown jewel of what Microsoft calls the "Windows Server System," Server 2003 is zircon, not diamond.

The "faster than Linux" claims are interesting. I wonder how it would benchmark against some of the newer development series kernels...