Me and my friends stayed recently in one of the Royal Court flats and can't complain about anything, it was really good!
Great location near Wenceslas and the Old Town, and the flat was big, bright and cozy, with a little kitchen with everything you need for a few days, a big bathroom and very comfortable beds.
The staff were also very helpful, and Ivan was very quickly responding and setting everything up for our stay.
I'd definitely recommend it!