i can see why আপনি wouldn't like him, and you're probably not the only one. i don't really HATE him, but i have this curse where i cannot hate any book character. =] he's not my thing though really. i like sweetness. and Jace is not sweetness.
I haven't read the last two বই yet, so I don't know much about him in those two. But I actually liked him, he was a great character. I didn't have a problem with him. But everyone has their own opinions, like with The hunger Games, I didn't like Gail অথবা with Twilight, I really disliked Jacob.