The arete forms the eastern rim of Cwm Glas Mawr. Climbed as a winter route sometime in Jan 1987 I think, and again as a summer route in July 1998 when overcrouding and queueing for routes put us of climbing on Cyrn Las.
Certainly one of the least known of the snowdon routes. I have only done this once and admittedly not by choice it was used during some summer ML training
From Ynys Ettws, I moved up into Cwm Glas, then turned left and up to the North ridge of Crib Goch. This was the final day of my 14 peaks traverse.
I've walked parts of the route (to get to Clogwyn y Person) but I have not walked the section between Llyn Bach and the Llanberis Ridge. Sorry.