Check out the new book on AE, Adobe After Effects 6.5 Studio Techniques by Mark Christiansen, the only real match for Trish and Chris Meyer's books. It even offering chapters on float and eLin. This book attempts to dispel the often unsubstantial myths about AE and visual effects. A 2004 survey found more than 250 Hollywood features had used AE, including many shots done at ILM and affiliates.
Visual effects pipelines can be demanding and break tools that seem robust, but AE holds up under strains of even IMAX production. It's not that you won't need other apps, like SynthEyes for 3D tracking, but if you're doing a mix of motion graphics and effects it makes sense to stay in AE.