Having involved in UAV development projects for agriculture monitoring and have used both rotary-wing and fixed-wing UAVs, I'm now firmly believe that neither of them is fit for purpose in aerial monitoring.
The rotary-wing UAV is a power hungry gussler while fixed-wing UAV is not that versatile (e.g. for hovering, etc). The best compromise will be Gyrocopter or Autogyro since it is both energy efficient and flexible. It can also easily fly at sustain high speed wind of more than 50 knots.