Rollando Villazón is not one of my favorite singers. I don't like is tone (timbre) and, im my opinion, his approach to some roles is completely inadequate.
After surgery to his vocal cords, the tenor came back to performances but with some vocal problems. Many people, included myself, thought that his carrer as a singer was seriously compromised, but after saw the following video from a concert in Liceu (Barcelona), I think now he is definitely back. The voice is in good shape, although I still think that is voice is not suitable for Donizetti.