Christina Ricci is amazing, the most professional actor I think I've ever met. You can be chatting with her and when they call action, she's right there.
Well, an actor is an actor is actor, to paraphrase someone or other and the opportunity to work, to have a steady engagement, certainly seemed like an appealing concept to me.
I think you can really tell a good actor if you can put a camera on them and they can just talk and emote and react and you don't have to keep cutting away from them, because they are the language and the behavior. It's all a tour-de-force performance.