Visiting Holyrood Palace is the first time I've been in a palace set up to be seen as a palace, that makes me think that I need to find new friends ;). I wasn't exactly sure what to expect, I have been to see the Hermitage and the Louvre, but since they serve as museums they are different. The palace, while quite lovely, was not quite as grand as I expected. You start the tour at an outside courtyard, which is very nice and then you enter the main building. The first stop inside is of an outside walkway around another courtyard that is enclosed by the building. From there you finally enter the palace.
Inside the palace I got the distinct feeling that there are spaces set aside for the tour, designed to represent different points in history. Then there are spaces that are still used by the Queen, there doesn't seem to be much overlap of these two areas. I would guess that at 2/3rds the tour was in areas dedicated to the tour and the history of the palace and of the Scotish and English royal families. 
After going through the palace you exit at the cathedral where you can again take photos. You are not permitted to take photos of the interior of the palace which I find frustrating. I'm sure there are several reasons for this, some better then others. But, my memory has faded quite a bit since I was there. I could have bought a book about the palace, but it would just sit on my shelf with the other books I've bought in my travels and maybe gotten looked at once or twice. I do remember the audio tour was very good, well paced and chock full of information without being overwhelming. I really liked the dining room and some of the other public types of spaces, though many were not quite as over the top as I would have expected in a palace. The rooms that were part of the history were also well done, particularly the areas designated for Mary Queen of Scots.
Who would I recommed to visit? Those who have never seen a palace before and for those who are interested in Scotish history. If you've been to a palace before and are short on time in Edinburgh, you might want to spend time exploring other areas of the city.
I did not visit the Queens Gallary, I'm just not a big art person so thought I would spend my time doing something else.
