I don't like his eyes or his voice, or that he gets more stretchy as the show goes on. I also don't like that he's the only heavily made up (make up wise) crew member. I don't find him particularly likeable.
I get that it's part of the premise though, that ENT is trying to be a more coarse, and under developed Trek, so of course most aliens aren't going to be signing up.
Speaking of which, I'm not really a fan of the Xindi as the bad guys.... it's almost like, it's all a Holodeck program Riker or someone is writing.