steady run 3:45:00 
With RC, good day, cold and windy but mostly sunny. From Glenmuick junction up big track then cut off to Craig Vallich (CP63) then along track (and first solid snow patch) to Cairn Leuchan (CP64), continued along track to south dropping into the head of Glen Tanar and up other side, some big snow drifts in track but pretty firm and good going. nearly to the wee hut and cut off across the peat hags (worst on the DR points so far). Seemed endless but eventually reached Head of Black Burn (CP68) and turned north onto some suddenly runnable ground. Realised just in time the ground isn't quite right and turned east to cross a burn and up to the real HoBB! Would have been embarrassing to miss a summit - and its a bloody long way to come back for it! Turned north and headed to the Quartz Cliff (CP67). Amazing vertical cliff in a wee corrie with nothing like it for miles around. Some great snow drifts in the top of it, but a bit steep/hard to try running down them. Crossed back to the big track and wended our weary way back up to near Cairn Leuchan retracing our steps (no real other option). Wind was at its worst dropping down the big diagonal track , but at least it helped cushion the legs a bit on the 2.5km descent. Still running at end, tired legs but nothing too badly sore.
Great day out with stunning views of Lochnagar and Beinn Avon/BheinnA'Bhuird in the sun with a covering of fresh snow.