The book can greatly improve problem solving skill. Too bad the soltions are not clear enough. 500 questions should take me around 2 months.

This is the only book about linear algebra form my library, I'm still reading it, so I can not give a exact rating right now. From what I have see, it is not the exact book I would want to use for learning linear algebra. The book forcous on the mechinical side of mathematics, like how to do operations between matrices. The book have a little help with enrich the idea of the matrix. For example, the book never talked about the geometric meaning of a determinant. After one reading the book, he might become masters at finding determinants and solve system of linear equations, but what's the point, even a TI-83 calculator can do it.
Get this book only if you want to learn how to manipulate matrix instead of understanding it. This book can be used as a nice outline of the course.