Seem to remember discussing this book a few months back so there's probably already a thread...
I remember the first half was DCF stuff, not extremely useful. I wish he would have spent a little more time with different valuation techniques. Dorsey and DCF reminds me of the phrase "when all you have is a hammer everything looks like nail".
The second half is the most valuable portion of the book, Dorsey goes through different industries and talks about the key metrics and key drivers for each industry. Each of those chapters is probably ten pages long or so and can be read pretty quickly.