This may be a good resource for professionals also - but they'll have to speak for themselves. As an amateur, I found the instrumentation section extremely valuable. It is primarily because of that section that I give the text 5 stars. After plowing through a great many journal papers I eventually found that most of the theory and practice of building an STM had in fact been nicely distilled by Chen. There are some minor mistakes (e.g. discrepencies between the text and some figures), but nothing critical that I could see. A number of disparate but relevant prerequisite topics are addressed in the appendices with moderate success.
If there is a peer or superior alternative to the instrumentation and design aspects of STMs, I would love to hear of it!