You won't get good range unless you keep a clear LOS between the aircraft & controller. Even trees & bare branches can significantly reduce range. Further you get Max range in a clean RF environment that is relatively flat like farmland & water.
That is impressive. I got about 500m out the other day and lost total video feed. I think its cause it was cold, starting to snow, and i had a decent amount of trees between me and the machine...what do you think?