I tried some random searching and Academic Search is missing many papers. But it does index some Elsevier papers, where Google never got the rights. But there is a back door in Google via ACM. For example, do a Google Scholar search on Occam's Razor, click on the Blumer et. al. paper and it will bring up the ACM Digital Library page that indexes the Information Processing Letters article. Click on the DOI bookmark and it will take you to Elsevier's page.
In short Microsoft has the much nicer interface but not yet the breadth of articles. If your sole goal is to download the paper, better to use Google.
A little less related to academics, you might want to check out Google's just released Calendar. Looks impressive.