These are exactly the kinds of questions we started asking when we were tasked to put more art direction into our thought leadership articles. The unofficial rules we came up with for pull quotes:

• Pull quotes should avoid the echo effect by occurring higher up on the page before the quoted text, essentially giving users a glimpse into the payoff of the article.
• Including a cite and a byline (even if it’s the author of the article) can also help with the echo effect.
• Inline pull quotes like your example can feel too disruptive. Pull quotes are a great time to break the grid.
• Design quotes in a way that pull you out of the article, but then puts you back in. Avoid garish colors. They should be an accent, not the main attention-grabber.