I think it all depends on your client and your relationship with them. If it's a large corporation with no relationships possible (ie, this is a hard learned l

I think it all depends on your client and your relationship with them. If it's a large corporation with no relationships possible (ie, this is a hard learned lesson in itself), I'd likely want as much in writing as possible. If you are working with a small shop with people you know well, maybe it doesn't matter so much?