I understand why his character was created and what role he was meant to play. Unfortunately, what makes Vaan so unlikeable is that fact that he is just so poorly written(and designed). Personally, I like the rest of the cast. I like the subtle nuances of their personalities and their lengthy dialogues. Their subtle personas grew on me throughout the game, and by the ending credits I had a good idea of what sort of people these characters were. That is, all except Vaan and Penelo.

I like Penelo, I like her character design, and I liked using her in battle. What little we did see of her I liked, but the writers just didn't do anything with her. She was really only there to validate Vaan's character. The trouble is, Vaan doesn't have a character! He was written as a stereotypical, obnoxious young street kid who is supposed to provide comedy to an otherwise serious story(and I admit, sometimes I did laugh at Vaan, but never with him...). What a chance the writers missed with both of these characters! They could have had Vaan mature considerably along the way, transforming himself into a mature young man opposed to staying that same whiny pirate wanna-be. And Penelo! Granted, I find her character(though hardly explored) better developed than Vaan's, but really---she hardly contributed to anything! *sigh* I love this game, but these two characters always get me.

So no, I don't hate Vaan. I didn't ignore using him in battle because his stats are great and he was useful in some of the larger boss battles. But near the end of the game, he really was just a drag on the plot when he should have been helping to propel it. I've done many a Squall facepalm when it comes to him, let me tell you.