I think that latest episode was okay, but far from the best.
My main gripe was that I had been hoping for the real Pinkie to take a more active role in getting rid of the fakes. The least she could've done was to somehow use her knowledge of how she would personally act to help round them all up. But instead Twilight Sparkle sorted everything out with her magic. I much prefer episodes where if one of the non-antagonist characters instigates a problem, they're responsible for fixing it (like in my favorite episode of last season, Ponyville Confidential). Still, there were some hilarious visual gags as is typical of a Pinkie Pie episode, and Fluttershy stole pretty much every scene she was in, so it wasn't all bad.