Gave me a slightly less dramatic version of that story at work on Tuesday.
My top tip would be to carry more than just a slice of Christmas cake. Maybe two slices.
The bit north of Inversnaid was virtually unrunnable when I tried it. Didn't i mention that chez Jarvis?
What is so bad about it tho? How bad can it be? I am intrigued.
Ray may have more recent knowledge, but my memory is ...
Very rocky, slippy, with lots of big natural steps and fallen trees. Because of the steepness and woods, you can't easily go round obstacles. You might run it if you were agile, fit, fresh and in dobbs. If you already ran 20 miles in flats, its going to bring you to a walk or else you'll spend a lot of time falling over.