I am NOT a Windows proponent; in fact, I have never been a proponent about anythings except, PXE, Terminal Servers, and Virtual Machines because of both the simplicity and resource exploitation they provide users for maximum advantages.
I do pay attention to performance reports found in the wild from sites like Tom's, Phoronix, etc.
I found this report where it shows the similarities of 3 Desktops against each other: Namely Ubuntu, Intel's Clear, and Windows Pro on a current Intel processor.
Surprising to see how close they are to each-other.
Enjoy