Academic Search is great, no doubt about it. It has articles from thousands of journals, magazines and newspapers going back a number of years. It is definitely an excellent starting point for your article search. But, sometimes you need more, and one nice thing about Academic Search is that if you click on the "Choose Databases" link above the search box, you can add other databases to your search!
This isn't all databases we get, just those we get from Ebsco, the company that we get Academic Search from. Say for example that you were researching affirmative action. Academic Search would be a good start, but if you were especially interested in affirmative action in schools you might do the "Choose Databases" link and add Education Research to your search, picking up education journals not all of which would have come up in Academic Search.
So don't limit yourself to just the one database; if you need more, you can get it!