Strangely, this was not informative. Part of that is due to asking the question of authors. The answers are bound to be similar, though of course, each hopes their option is the best. So the graph doesn't really tell us much either.
There are glaring differences: self-publishing gives you a much larger share of the money but fairly limited distribution. (If you're midlist author, distribution through traditional channels is also poor, since the books don't stay in stores.) Control doesn't exist with traditional publishing. Promotion is miserable either way.
Interesting. But no discussion on whether or not some authors choose self-publishing because they haven't been able to get published with a traditional publisher. Ms. Ward may be a talented writer, but not all the titles that are self-published are going to be quality. Who does the editing for these books? I wouldn't trust myself to look at my own work and say, "Yeah, that's good enough".