Never stayed at Skibo ($$$$£££), but do enjoy Gleneagles. A bit strange I admit, but the golf is very good. That said, probably the worst in-room shower I have ever had !

As for Ackergill, it's a bit close to me for a holiday, but I have heard it described as being in The Beardy One's top ten list for all the world.

And there are a lot more very exclusive/discrete places to stay in this part of the world as well (ever heard of Drynachan?).