I kinda liked it. But...
I didn't like the song that much. Or the 'professionalism' subplot, especially the ending, although I guess it's in character for Harshwhinny to do a sudden reversal like that?
Still, the CMC are cute. And I *did* like Rainbow Dash's enthusiasm. Maybe her being forced to suddenly cut it off was why the professionalism stuff annoyed me.
"How are we going to stop them? We already called them blank flanks."
Which reminds me... I liked Diamond Tiara a lot better in Ponyville Confidential when she was horrible and evil but wasn't just being a one-note antagonist. Yeah, okay, she had a *reason* to be awful this time -- she was trying to sabotage them so that she could win -- but it's still not really fun to watch unadulterated bullying.
In short, I think the episode needed more Pinkie Pie. But I think that about every episode.