In reply to johndevlin:
John - if you want to make a good day of it, and get as much scrambling in as you can, then turn right at the top of the arete and go up the Gribin (keeping on the crest, otherwise you spoil it). Walk round the Castle of Winds, then scramble down (much more fun than going up) Bristly Ridge, up on to Tryfan and then down the North Ridge. It's a long day but great for fitting in lots of scrambling.
(also, if you can climb V.Dif, why not start up the Ordinary Route on Idwal Slabs, then traverse across to the bottom of the arete - that way you'll hardly step off rock all day!)