The most dissappointing exhibit at a palace was Kensingston Aug, 2006 - Princess Margaret's apts - what a rip off and a joke - there was nothing left! "here used to sit a chair of Princess Margaret etc. etc. the whole audio tour". it coincided with my visit to the "Diana" Testino exhibit which was a tad better.
I saw it too that same year! And I agree with you.
I went to Hampton Court as well during the same trip. Very nice place, and supposedly haunted too. I must say, even before knowing where I was, I didn't feel well in the Haunted Gallery...
And if you love palaces, Versailles, Fontainebleau and the Louvre are nice to see! Let's not forget the Loire Valley castles, from different times, but absolutely lovely...
For example:
Chambord Castle, built by King François I (it's a bit empty inside, though, but there's the famous 'magic stairs" created by Leonordo Da Vinci),
Chenonceau, above the river Indre, often occupied by Queens and royal mistresses :
and many more...