I don't know how useful any sales figures from a single site are, one way or the other, since none of that will give a good bird's eye overview. That said, drivethru is probably one of the best single sources for a general impression. Finally, people spend money stupidly, and gamers as a category are especially proficient at it. I couldn't begin to speculate whether the edition is selling well or not overall.
What I can speculate on is the quality of the work. Anyone can fairly argue whether they like the direction or dislike the direction of the rules - that aspect is just a matter of personal tastes. We all know where I fall on that, so no need to rehash. I see a lot more criticism than praise spoken about it online, and hear the same in person when the topic comes up. But again, how well does that represent the overall opinion? Hell if I know.
The state of editing they allowed the book to go live in is indisputably, unacceptably bad. There is no acceptable defense for that.
That quote by Matt Colville is also among the most foolish things I've ever heard.