It's a book that is written more for JAA regs. Which has some different rules and such, but I wouldn't have catorgized it "a lot of wrong information". Some isn't applicable to the FAA regs, but the majority is perfectly adequate.

I studied primarily the aerodynamics and the performance sections out of it.

It worked for me no problem.

I used that book, the AIM, Instrument Flying Handbook, and Turbine Pilots Flight Manual, and Mental Math for Pilots.