Your comment about depth is right on. Timothy seemed unidemensional. Stone killer, but very little smile.
The problem with Moore, Dalton and Brosnan is that they always seemed to patrician for the actual job. On the other hand, I think that Brosnan in "The Tailor of Panama" is a great look at what James Bond would actually be in the real world--a scummy little extortionist and con man who thinks he's smarter and more charming than he really is.