Think Puffins have been vastly oversold. Stupidly long wait times (presumably cos new installs hence "traffic flow" prioritised). So a lot of people chance it hence second flaw - that whole thing where the Puffin cancels itself if the pedestrian crosses before the red light - doesn't work, at least not reliably. I get stopped by an empty Puffin (relatively new) on Fountainbridge around 50% of journeys.
Good piece on other flaws here:
https://aseasyasridingabike.wordpress.com/2016/09/14/the-problem-with-puffin-crossings/