Okay so I did like this book, but this is a more of a 3.5 stars because I did have issues with it.
So Applejack is set on making her orchard look amazing so she can win a contest. She has big plans and ambitions, and her friends want to help, but instead they slow down the process and frustrate her. Applejack, though occasionally sarcastic, doesn't really show her distress and instead writes about it in her new journal.
I could completely understand Applejack throughout the whole book. It's hard to have high expectations and then to see them disappointed when it's something important to you. Especially when it happens five days in a row. But instead, there comes a point when Applejack thinks to herself that she's being unfair to her friends. Except...she totally isn't. They ARE making her work more complicated; the real issue here is that she isn't communicating with her friends.
Her friends accidentally end up reading the diary, and they see all the mean things she wrote about them. They aren't really mad, though. Everything is patched up pretty quickly, and Applejack says, "I was bein' a huge jerk and letting my own ambitions get in the way of the most important thing - my friendship with all of you."
Uh, no??? She wasn't compromising her friendship by being ambitious, and she was never a jerk. Her friends were jerks for continuing to read her diary once they figured out what it was, actually, which they never apologized for. (Although Rarity did crack me up by commenting that her diary is way worse.)
The book was realistic and emotionally resonant, and there was a good lesson in there, it just didn't quite hit like it should've. Applejack is such a fun pony to read about and this insight into her thoughts was nice. I just wish her story would've been done justice!