In reply to Y Gribin:
The track is much easier to follow, and much better underfoot, than the direct descent in the dark at the end of a long day. I've gone up that way when going N>S but am pretty sure coming down there at the end would be more of an embuggerance.
There's also a handy small car park further east, accessible from the Conwy side of the valley, down by the Rowen turn-off. This is closest to the end of the traverse.
Don't do what we did and accidentally lock the car keys in the car (with the headlights on); smashing the window on your new car to get back in at the end of an otherwise brilliant day wasn't really the highlight!
b