My biggest complaint for this movie is that the story seemed very weak. No one really cares enough about M to see her in this much of the movie, and no one wants to watch James Bond spending this much time trying to protect her. We want to see James Bond doing spy things, not babysitting M.
Other than the weak story, I guess it was a decent action movie, as far as Bond movies go at least. It felt really, really long though, like they could have cut out about half an hour or so.