I absolutely love this mapping tool. Just did a run north of Aberdeen and the suggested route was excellent, using the many back roads and farm tracks in the area.
I'm reporting one that no-one else will probably come across but just in case, at the coordinates 57.3767,-1.9806 there is a bridge down which leads to a 'back the way you came and go a slightly different route' detour. It doesn't look like it will be replaced anytime soon.
Looking forward to my next backroad adventure :D