In reply to Dakin:
Probably a much nicer walk to go up the CMD arete, assuming you're not planning to go up one of the routes or scrambles on the north face.
Bit of a slog of an uphill to get to the start of the rocky part of the ridge but you have the best side of the mountain right in front of you the whole way, making the walk feel somewhat atmospheric as you look across at the north face. I've done it both ways and coming down it is a bit "Meh" IMO and it involves trudging up the tedious main path.
P.S. OS maps are just great if you know what you're doing with them....;p
Post edited at 15:51