Simple colors, and AJ is very well recognizable. Yeah, I really like the simplicity on this one. Which is a bit of an irony, seeing how its also more "realistic" then the show's actual style at the same time. I guess it's what would happen if an "Earth"-horse 'went to Equestria', so-to-speak.
This is really good, btw, I was going to do all the mane six in realistic style, but since you've done applejack already I'm debating wether I should do her too or not. So far only done Dashter and the Shy, kind of getting burned out already.