These are the "good stuff" .. for various data gathering activities you do not want a fast high flying jet, you want a slow close to ground platform travelling at sub 70 m/s speeds to maximise "dwell time" over each ground point (while not travelling so slow as to fall out of the bloody sky).

Crop dusters carry weight, excel at STOL (Short Takeoff and Landing) on "Oh shit, that's not a runway".

US Special Operations Command is into the sneaky stuff - intelligence gathering, quick in | out person on ground infil and exfiltrates.

Stubby little planes that pull like tractors and can depart flying upside down underneath a bridge are ideal, they get overshot by fighter jets and have engines too cold for air to air missiles (fingers crossed).