In reply to Superterence:
I did it years ago, although not right from sea level at the north end. Mainly scrambling, with one or two moves approaching 4a/4b. We soloed but a cautious person might need a rope for some sections. We did it in shorts and legs got quite scratched, so plus 2 for the trousers recommendation! If you were using a rope, as Phil Murray warns, take care, because the sharp rock could cut it in the event of a fall.
Having said all that, it is a fantastic adventure with mind blowing exposure particularly on the west side.