On the weekend I was in an area of pine plantations and detecting over where trees had been removed and the ground ripped by dozers. I flew the drone and could see colour changes of the soil (ironstone bands and old diggings that had been covered by pines).
I then followed a gully which lead me to some diggings that I hadnt seen before and arent on maps. The drone is working out real well!
On a side note, it was quite windy and I think if I had bought the Mavick instead of the Phantom 4, I would have struggled to fly it.