We haven't walked the whole route, but we've walked the section from Hawes - Askrigg - Aysgarth on a Wensleydale-Swaledale backpack and the high Mallerstang section from High Seat to Little Fell more than once.
The Mallerstang section is excellent, if a bit rough and potentially boggy around Little Fell, and that dale section is typical Yorkshire Dales valley walking.
I notice that in the dales the route often follows footpath segments that are not evident on the ground, according to the OS 1:25000 mapping, I don't know if these would cause any problems.
