No, you don't. The 64GB MBA Air I bought was using not even close to the 40GB used on the Pro. (think less than half this).
If you're talking about starting fresh - A clean install of Mountain Lion (6-7GB) consumes less than half the diskspace of Windows 8, so how is your scenario possible?
You're never gonna get it down to 6-7 GB, but you can get it under 20 pretty easily
http://pocketnow.com/2013/01/30/how-to-free-space-surface-pro#disqus_thread
Personally I think they should've just made the 128 GB version the only model. It's a high end device geared toward power users that will probably be picking up that version anyway
Lol the Surface Pro is a fail. It is $300-$400 too expensive compared to tablets.
Why would anyone buy a Surface Pro for the same price as a MBA?!?!
It's a converged device - tablet slash ultrabook slash with an integrated wacom. Plus access to two software ecosystems - mobile and desktop
It's shortsighted to compare it to the MBA or to iPad. It's as if the smartphone is coming out and people are going, a PDA costs the same but has a better battery, or it's $300-400 too expensive compared to my feature phone. It's a brand new product space that'll disrupt both markets