According to PC management services company Soluto, "in the field" testing has revealed an Apple-built laptop to be the number one performing Windows machine as of April 2013, despite not being optimized for the operating system. From Apple Insider:

In its first ever report, Soluto (via CNET) looked at long term analysis of a "huge number" of PCs, gleaning data from application crashes, freezes, long boot-ups and other general computing slow-downs in what it called "frustration analytics," and found Apple's 13-inch MacBook Pro to be the best Windows laptop available.

 Apple's MacBook Pro named 'Best Performing Windows Laptop' by IT company