Summer, that's why I didn't post a link to Will Gompertz's review. If you watched Mark Kermode's review I think you would find that it's much closer to your thoughts. The original Mary Poppins film is one of his all time favourites - he's seen it over a hundred times. So he had some misgivings about the new film. Initially he thought it was very good but about 20 minutes in he realised that he was crying because he had become so emotionally involved with the film and he came away from the film loving it.
Don't expect the Emily Blunt version of Mary Poppins to be a carbon copy of Julie Andrews. I think it would be closer to how Emma Thompson would have been like if the film had been made say 15 years ago (and I don't mean like her Nanny McPhee).