I don't know if I'm having the same discussion about the incidental music, but I don't care whether it's loud or quiet, the score itself is too obvious and manipulative in my opinion. I've watched it in HD with surround sound as well, and I still feel the music is intrusive. A score should enhance the atmosphere, emotions and actions, but in my opinion, Murray Gold simply overpowers everything.
I've watched the episode a couple of times now, and I think it was a good, solid episode for a new Doctor. Not only did we have a new Doctor, we also had a new companion to introduce as well as their background and surroundings. This means a domestic style of episode, set on Earth, action without too much peril, and the opportunity for some good humorous scenes. Overall, I think they got the balance right.