I couldn't tell you if this book will make you a better trial lawyer, since I'm not in practice. The text itself is plainly wrong at points, but these points have little bearing on conducting a trial itself. It's just that it's quite lazy to get terminology wrong:
"Most people are also deductive, not inductive, reasoners. That is, they are impulsive, use a few basic facts to reach decisions, and then, accept, reject, or distort other information to fit their already determined conclusions." (p43)
The point of these sentences is to point out, hey, some jurors will decide on the basis of their own biases rather than the evidence that comes out at trial. That's not wrong. But it is wrong to call this deductive reasoning. I can't for the life of me figure out why the author felt the need to use this term. Deductive reasoning is usually an argument where, if you accept the premises, and the conclusion logically follows from those premises, you must accept the argument. "Impulse" or information distortion has absolutely nothing to do with it!
And since this came so early in the book, I had a hard time taking the rest of the text seriously. It's a competent enough text, I suppose. Most of the work at trial is simply... practice, practice, practice, and be sure to write everything down.