At risk of being accused of moaning, I must confess that I've never really been impressed by Gibbs when I've seen him. He looks pacey and athletic but his final ball is pretty poor and he positioning and tackling is only ok. I don't follow Arsenal closely and this is only my recollections from watching them on MOTD and Champions League. I'm sure our coaching team have done a lot more due diligence than that!
It's hard to feel a bit down after signing a full England regular international with CL experience but I've just got a nagging doubt that he might not be as great as his billing. On the other hand, if there's a defender somewhere in Gibbs, Pulis is the man to make the very most of it!
Welcome to the club.