I don't know why everyone is so obsessed with seeing her being fed 'humble pie', I mean sure RD is boastful and thinks she's awesome but that's her character quirk and what makes her special.
If you took away Dash's attitude and pride in herself she would be pretty bland. Every pony has her own annoying fault, like Rarity's over the top dramaticness and Twilight's OCD. I admit that I don't like Pinkie much because of her quirk, but I can see why people do like her and I wouldn't want her to be changed.
Rather than bringing Dash's pride in herself down a notch, I like when she's forced into choosing between that and things that are more important, which was definitely a theme of ep 7. I know we've also had episodes that served to show Dash she shouldn't be so boastful all the time, but I really prefer her acknowledgement that there are more important things than how awesome she is to simply acknowledging that she is too prideful or not as awesome as she thinks.
If that makes sense.
I dunno, I'm paranoid, overly critical of myself and the opposite of a risk-taker so maybe RD exemplifies all the things I wish I could be - courageous, full of pride in myself and not afraid to take risks and live fast sometimes.
As for the rest of the episode, Pinkie was kind of annoying and I wondered what the point was of taking focus away from the main event of the plot to show what Pinkie was doing. But of course, it became clear at the end. I understood why Dash wanted to be lead pony, even though it's a small discrepancy - no one wants to be second best when they are chasing their one and only most important dream. Everyone wants to be special.
I am kind of disappointed in how shallow Lightning Dust turned out to be, simply a plot device for RD's own triumph, but it might be interesting to see her again as a more developed character.
At least the Wonderbolts are showing up again. Of the Mane 6, I think RD is the only one who has a well-defined, achievable goal or dream. It would be nice to see her join the Wonderbolts before the series ends.