I have the opinion that it is better to have roads in the map than not in the map. My time and radius are limited so I have traced some villages that I know (though not terribly well) but haven't had time to visit yet to fully map them.

Conclusions: OS StreetView will help get a base map in place. It is definitely not as good as manual collection of GPS data or tracing aerial photography but it has the advantage of making places appear where previously there were blanks.

I will fill in details in due course but for now, it actually appears which is better than it was before.