The mapping does show some of the OS features but far from all of them.
It includes contour lines and paths and types of vegetation. The map set is built on the City Select v7 mapping and does include turn by turn capability for roads but not for paths.
For a walk in the hills the Topo mapping is a huge improvement (over previous mapping) but for road use I am undecided whether City Navigator v8 or the Topo is best.