My background: Computer science / mathematics undergraduate with experience in calculus, discrete mathematics, and differential equations
Leon's text on linear algebra isn't bad, but there is room for improvement. Chapters 1, 2, and 3 do a good job of introducing the basic concepts of linear algebra, including matrix row operations, determinants, and linear independence. The book seems to lose clarity beginning in Chapter 4. The concepts become more abstract and Leon's notation interferes with the ability to clearly understand what he is talking about when it comes to linear transformations and issues regarding R(A) and orthogonality. Very important results are frequently understated as well. In a few cases, there aren't enough examples to go around - especially in Chapters 4 and 5. It is ironic compared to the relative overexplanation found in Chapter 1, for example.
Another qualm I have with this text is the chapter review sections, which are limited to MATLAB exercises and simple true/false questions. I think these sections need actual math problems devoted to them that force the reader to combine and use concepts learned in the preceeding chapter, rather than overly simple true/false questions.
On the other hand, the homework problems the book offers for each section are fairly worded and interesting to solve. There is an answer section, of course, for the odd numbered exercises. Also, there are several "Application" sections that demonstrate how linear algebra is used in real-life scenarios that provide a relevance to this study, just so the casual student doesn't wind up wondering "Where am I ever going to use this?"
The book is just okay, but it needs a really good professor to go along with it and elaborate on the concepts Leon either understates or fails to present clearly. On a side note, my book is only two years old (I bought it like new) and the binding is already falling apart.