I’ve done it a couple of times in the past.
The top section is singletrack and very broken up in places, so a few dabs are in order. It flattens out for maybe a mile before the ‘quarry’ section which is pretty rocky at the top, followed by some fast switchbacks. Once you hit the bottom of the quarry its quick road/bridleway in Glenridding.
It’s got a bit of everything and I found a real challenge, especially the first time as it was after about 8 hours pushing and riding. Some of the folk on MTBBritain really rate it and I know they are riding 95% of it (good work on that top section).
Well worth doing if you ask me.
Matt