I am one of those few who much prefer Origin characters over Tavs and so far Gale has been my favourite. But I'd also say that my great enjoyment from having him as a PC comes from the character himself and the interactions with the other companions. For example: Whenever the narration tells you Mystra would approve or disapprove of something, you can be certain that Astarion has either just tried to convince you of the exact opposite or will do so in a bit. It's not - or at least not just - the final decision that makes him interesting for me, but coming to terms with his issues along the way.
