I like the Academy. It is a good way for players to practice the correct fundamentals that most winning poker players possess.
However, it can get you in trouble if you're doing the challenges ONLY for the academy points because you'll be making plays that may not be optimal against the types of players you may face.
Example: In one of the cash games challenges Chris Fergosen tells
you to raise certain amounts in certain positions. If you have a lot of loose players at your table who call smallish raises with a wide range of hands, you should raise more than the amount Chris tells you because you want to thin the field and try to get your good hands heads up.
Just something to think about when doing these challenges.