Not being a fan of Pinkie Pie, I didn't care much for this episode. It was perfectly titled, IMABNQHO.
One thing that bugged me was the deal with Spike finding the button behind the books, and discovering an old and dusty book. What was up with that? They've emptied the shelves multiple times, so they should have found that button before. Why didn't Twilight Sparkle question where that book came from?
The zapping of the fake pinkie pies also seemed kind of cold-hearted and ruthless to me.