I just turned in the next iteration of the manuscript for my little book about RTF. The tech editors were extremely helpful in finding all sorts of things to fix, and in suggesting things to clarify, further examples, and so on. I couldn't use every last suggestion, for reasons of space mostly, but at least 95% of the comments were spot-on. My little coterie of tech-editors were:
I have a great editor, Linda Mui, and a great illustrator and graphics-slinger, Robert Romano.
Now you just have to buy it. It's the best book you didn't know you needed. Right down to the origami CD case in Appendix F.