In selling the Surface Pro, Microsoft’s marketing team has a big challenge. The new tablet is essentially an Ultrabook in a tablet’s body. But most customers are going to look at it and think “iPad competitor.” We already compared Surface Pro to the iPad, but perhaps a more appropriate comparison is to the MacBook Air. Let’s see how their specs – and other features – compare.This comparison covers the 11-inch MacBook Air with entry-level specs. Apple offers upgrades with superior components, but we’re leaving those alone here.Compared to standard laptops, the MacBook Air looks small and svelte. Next to a tablet, though, it’s rather large. It’