I don't really disagree with any of that. I've done both ways and I'm not sure I'd go with a traditional publisher again unless doing so fell in my lap for some reason.

Another thing I find for tech-related books--which is what I do--is that if I do things myself, I control the length whereas publishers generally have a minimum number of pages in mind which may be more than the topic really warrants. And a final point is that, as an individual, I have more flexibility in just giving copies away (especially ebooks) if I did the book mostly for promotional purposes.