NCN 70 is "Walney 2 Wear", but W2W can also be "Walney 2 Whitby", and that's NCN 165 - an alternative eastern end to this coast-to-coast route.
The Tees Valley past Barnard Castle and Darlington is a delight, with little single-track roads meandering from village to village, pub to pub. You could make a lovely weekend tour out of this without too much exertion, perhaps taking a detour south towards York.
But W2W is a tough route and the Whitby finish tougher still, and after Great Ayton come some gruelling climbs over the North York Moors. The views from the summits are fabulous, and the precipitous unpaved descent to Eskdale is certainly unforgettable.