re:
To me, this question should be more a comparison of the Surface Pro 2 to the Yoga 11S, since the Yoga 2 Pro is a larger machine than the Surface is, and the 11S is a more direct comparison.
Personally I went with the 11S because I will do a lot of typing, so the removable keyboard isn't all that much of a need for me. On top of that, to get what I got in the 11S I would have spent a lot more getting the same with a Microsoft badge. If you look at the 11S that Best Buy is carrying (which for some reason is not available on Lenovo.com), you get the i5 Haswell, 4 GB RAM, and 128 GB SSD for $800 (I got mine last week for $750 on sale, though). Microsoft can't compete with that price, so unless a person is going to use it without keyboard most of the time, my personal feeling is that the 11S is a better buy. Your feelings may differ - I'm fine with that. :wink: