I don't know what you know.

I haven't run it - only walked it. 100 miles from Glasgow to Fort William, mostly very good trails - some steep climbs such as the Devil's Staircase, but they're not really too bad.

The weather can be very bad, and Rannoch Moor can be desolate in winter....and in summer.

There are a lot of b and bs along the route, as it is a very big tourist draw in the summer, and it can seem quite crowded, but pretty quiet in the winter.

There is a race - usually on the longest day of the year.

Mike Cudahy writes of his running it in his famous book about running the Pennine Way, which i think is called 'Wild trails to far horizons' - a great read.

You probably know all this. It is a great holiday - good luck.