Beolab, I've dropped my sharpness down to 12 and it seems a good compromise between good quality SD broadcasts and HD. Tried 10, but HD seemed to suffer slightly (not as sharp).
Watching Chronicles of Narnia right now - mainly for the PQ - on Sky One HD and I can't see how it could be bettered. Absolutely superb PQ.
Now, I only wish the BBC would show the FA Cup on their HD channel as they did in 2007 :(