Microsoft Surface Pro user storage actually on par with 128 GB MacBook Air out of the box, test finds

It turns out that not only is the free space on the Surface Pro comparable to the one on the MacBook Air, give or take a couple of gigs, but if you move the recovery partition to a USB flash drive or similar, you'd actually have more storage for personal data than on Apple's slim computer, and that's with fully accounting for the different ways Windows 8 and OS X measure storage capacity.

source: ZDNet