I prefer Equestria Girls. Equestria Girls had more plot variety and better character development for its characters, IMO. And the music was better too.
It's pretty cool how they made all the sciencey-stuff she says actually accurate. She's an interesting character and says a lot of interesting facts in the show.
She's always able to help her friends even if she overdoes herself. And if her friends are upset she focuses on them and gives it her all to make them feel better.
Best EG character, IMO. She's strong and smart, and she can admit when she's made mistakes, but doesn't let them define her. And has the best character development in the series.
The op post one appears to be closed, so here's a link to a new petition I found:
https://www.change.org/p/boulder-media-can-boulder-media-save-the-equestria-girls-series?