I have an iPad 4, a Surface Pro, a Macbook Air 11", and a Thinkpad T410s (slim 14" laptop).
For taking notes and doing real work, I'd buy a Macbook Air either size or an equivalently small Windows laptop, no question. The new Macbooks really have the advantage of the new Haswell processors giving them a tremendous advantage in battery life.
The Surface Pro has a great screen, but Windows can't handle scaling properly yet, so it's always a compromise. The keyboards aren't great, and the battery life is mediocre at best, meaning you need to carry the power brick with you everywhere, greatly reducing portability.
For taking notes and doing real work, I'd buy a Macbook Air either size or an equivalently small Windows laptop, no question. The new Macbooks really have the advantage of the new Haswell processors giving them a tremendous advantage in battery life.
The Surface Pro has a great screen, but Windows can't handle scaling properly yet, so it's always a compromise. The keyboards aren't great, and the battery life is mediocre at best, meaning you need to carry the power brick with you everywhere, greatly reducing portability.