Having read "Understanding Exposure" I have to say I really like his writting, but the approach is somewhat limiting.
What I mean is the book tells us how he got an awful lot of shots in various situations, but as you grow you need to formulate your own thinking process and not replicate the decisions of someone else. So, for me, there's a step missing here.
It's a great reading for anyone, but advanced readers will need extra help to get going...
i think that is what makes his book perfect.
after all it's really a beginners book
for some in the beginning too much information is daunting
and the fact that it is one of the most read/purchased/downloaded books on "understanding exposure" says it all....on photography for that matter