For me it depends on the content and my mood. With my app [0] I read at about 5-600wpm, whether it's 1, 2 or 3 words at a time. If I'm having trouble with a particular article, changing the number of words often fixes it. Though of course, for some content, I need to drop the WPM (esp when there's a lot of technical and/or unfamiliar terms).

[0]https://play.google.com/store/apps/details?id=com.hughesoft....