In this interview David Tennant discussed Broadchurch (which was going to premiere the following month), his stage work and movies.
The interview concludes with 'Perhaps his apparent self-assurance is what made him such a good Doctor Who. However eccentric his career might appear, he's happy with them. If people enjoy his project, even better. If they don't, that's ok too.
David Tennant is unusual indeed: an actor as happy in his own skin as he is in anyone else's.'
Link to read the full interview