These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base: The Spacebattles forum inevitably gets horribly heated whenever the topic of the fic is brought up. Some love it, some despise it, all have incredibly strong opinions on it. Fim Fic users also have strong opinions on the story, but are far less vocal about it.
Though no longer as much since the SB/SV fracture.
Jerkass Woobie: Each of the mares in the COMBS arc, in one way or another.
Rarity and Silversteel cross into this once we learn how they treated DJ and her family during their reunion with her. Rarity has been considerably more persistent about the "Jerkass", part, while Silversteel has begun to make amends with them.
Magnificent Harridelle: Champagne Dreams a.k.a. Sunset Shimmer. There is nothing that she won't do to protect her family, even destroying every other family on the planet.