It's fabulous.
I prefer it south to north, cos then you can ride down the Mad Mile to Square Corner.
But you can join it at Osmotherley, and it's good going to the top of Boltby Bank. Bits of it were taken over by the Sutton Bank MTB centre, and the section above Boltby Forest is now ridable - it was a quagmire for years (much like Boltby Forest).
You could also park up at Swainby (decent cafe at the Rusty Bike), and ride along to Osmotherley along the trails from Cod Beck Reservoir.
The cafe at High Paradise is pretty good as well.