It seems to start promisingly enough at the Gladhouse end.
http://www.geograph.org.uk/photo/1812147
But then this happens:
http://www.geograph.org.uk/photo/1812125
Looks a bit better further east:
http://www.geograph.org.uk/photo/4684212
http://www.geograph.org.uk/photo/115490
I've never walked/cycled that route so someone else may be able to say differently.
I do remember trying to do a little circular walking route near Mauldslie years ago which probably involved the first wee section of the route.
We tried to cut across country to pick up another track to the west but were chased down by the furious land owner (from Mauldslie?) who chased us down at speed, off road in his 4x4 (with snarling dog in the passenger seat), who told us we couldn't walk there as we were putting nesting birds at risk.
Once he saw us returning with tails between our legs he roared off again, crushing another selection of fauna beneath his tyres.
This was pre-land reform of course.