Apartment is in the perfect location, walking distance to everywhere we wanted to go. We were there whilst the tattoo was on at the castle so we got to hear the music and see the fireworks every night. There was also a screen on the window in the bedroom that did a great job at shutting out the sound from the outside.
There are quite a lot of stairs to the apartment, which was ok for us, but might be difficult if you have mobility issues or a lot of luggage.
The only real negative about the apartment is that the wifi was terrible.