Here's a simple rule of thumb:
Never use three pages of complicated mathematics to explain that which can be explained using either a simple picture or a short snippet of pseudo code.The section on "Converting an NFA to a DFA" had me at the point of tears. After a couple hours, I finally understood it. However, even after I understood it, I knew I could do a better job teaching it. A little bit of Scheme written by the SICP guys would have been infinitely clearer.
I hate to be harsh, but it seemed like the author was just having a good time playing with TeX. I picked this book because it was short and didn't dive into code too much. What I found is that it uses math instead of code. I'd prefer code.
The worst part of reading this book by myself is that even if I make it to the end, I won't know if I truly mastered the material because I won't have a compiler to show for my work. After all, there's no one around to grade my written assignments, and the book doesn't actually take you all the way through writing a real compiler.