Clicking through some ads reveals there's now a flood of banging good GPS autopilots out there, being marketed towards RC pilots. They're a lot more stable than anything I could afford, owing to the latest GPS module, barometers, & the arducopter source code, which they all undoubtedly copy.
http://www.banggood.com/Walkera-G400...7-p-89151.html
Gone are the days when someone would tear them open & study the part numbers. The new customers are RC pilots with no idea what's inside. It wouldn't be surprising to find uBlox-7 & MS5611 in all of them.
http://helipartsdirect.com/blade-350...l-blh7880.html
Even the mighty Horizon Hobby finally caved in & started selling a GPS autopilot, though marketing it exclusively as a return to home feature.
The trick with autopilots is once you have one, now what? They're good at making timelapse movies. They can fly to places that were impossible for a human to reach manually, but the newest FPV systems make those places accessible for a human.
They're supposed to be good at returning to home when contact is lost, but there's very little evidence of that being used. It's still a lot of trouble to wait for GPS to lock on, make sure everything is calibrated correctly, just for that 1 feature.
There was some energy behind the following camera concept, but they probably weren't accurate enough to do a good job. Now there's hope for massive agricultural demand.
Autopilot for an RC pilot can get pretty boring, once the novelty of seeing it hover wears off. Hobbyists who design robot algorithms still seem to be the mane customers.
It was suprising that the mane media avenues: tested, flite test, rcmodelreviews were completely devoid of the GPS autopilot boom, emphasizing indoor quads instead. Even the mighty black sheep became famous not because of an autopilot but manual control.