I do not have the experience to listen to the Kingdom series but it is still high on my whising list.
The Kingdom is designed to listen to in close range, like a monitor. In Japan they have small rooms and maybe it is designed for Japan. Fact is that is it well suited for them off course. The sound is suppose to be very, very ipressive, as with the Kingdom 18 I can imagine with a 18" bass driver.
Compared to the Edinburgh they sound more alive and less laid back, but that is my interpetation. From what I have heard the best Tannoys are still the Westminster Royal and they belong also to the Prestige series.
Sorry, not much experience is listening to the monsters myself.
I guess the best is to get a listening session somewhere in the neigbourhood. And do not forget to take your favorite and well known cd's!