I liked this episode. Not bad, but not extremely good, just ok, and I like that.
Don't get me wrong; there's plenty of things that I though were pretty cool in this episode. First and foremost, I love the Wonderbolt Academy itself. I like the boot camp feel of it, and all the disciplinary aspects of it too. Also, I enjoyed seeing familiar background pegasi like Thunderlane, Snowball, and Cloud Chaser. And Spitfire; I think her portrayal as a Wonderbolt drill instructor was rather nice, suits her well.
Pinkie Pie was her usual self, no surprises there, lol.
Rainbow Dash, I believe, has shown that she has come a long way since the first season. She's still can be brash and competitive, but (in this season in particular) we have seen her compassionate side (with Scoots last episode), and we have seen her courage reiterated in this episode. Dash, displeased with her partner's methods of completing the exercises, speaks her mind to Spitfire (one of her idols) and proceeds to quit the academy. She willingly quits something that was her dream from the get go, in favor of her admirable morals. That took guts. It all worked out for RD in the end, so that's good.
And then there's Lightning Dust. All I can really say is that she was a necessary foil to Dash in this episode. While they shared the same drive and competitiveness, Dust had a clear disregard of the other cadets and only thought of the success of herself, whereas Dashie saw her recklessness being 'rewarded', and wanted nothing to do with it.
So yeah. Good character development for Rainbow Dash in this. Always nice to see.