Much of the complexity in the craft is centered around keeping the poor bastard flying it, alive. Then there are pretty tight limits on how much acceleration the human body can receive. Pilot-less craft don't have those limitions, so I figure they should be much more maneuverable and less expensive.
Conventional fighter jets have more speed, travel and strike range, and more maneuverability. They will outflank drones every time -- I'm not kidding, they stand absolutely zero chance against fighter jets.
You could send a couple dozen Reaper drones out and a pair of Su27/F15s would shoot them out of the sky before you can say "Hellfire."
Not to mention modern anti-air defense systems would chew through them like candy.
What are they good for then? Cheap, high-altitude, medium-range (~1500KM), endurance (>24hr) missions.
I'm sure they might ultimately get to fighter-jet performance, but at a much greater cost and reduction in mission time.