I think you should plan first what you want to do in RC hobby.
- If you want working out of box "push a button" filming platform, then DJI Phantom line is what you are looking for.
- If you want race, then build your copter and use Basic flying modes.
- If you want an autonomous flying and DIY copter then it is a completely different story and you will need to learn a lot period.
Why ? Because every DIY copter is different, it's not mass production that can be tuned, optimized and all is the same. Software has to handle all wired things user may come up with and yet work reasonably well. Most of problems come from lack of knowledge which is related to NOT reading, or not willing to read Wiki combined with huge expectations that everything will magically work.
There are two most common fallacies that people fall into
- Quad-copter is not flying well in Basic complementary (this uses just gyro and accel in attitude mode)
- Quad-copter is flying well in Basic complementary but other sensors are not calibrated properly.
To
begin with (1). Flying with Complementary that uses just two sensors is easy. It should work out of box if your build is solid and well balanced. For example I can hover 1-3s in place (without wind) even put transmitter on grass and pick it up, without huge drift of copter position. I am not using any crazy super-duper sensors here, just good solid well balanced and calibrated build.
If your copter is not flying well in Complementary (Basic) then it will not fly better with GPS. Why ? Because you have more basic problems and by adding GPS you attempt to add complexity on something that is not working. GPS won't magically fix that. Why ? Because autonomous flying is NOT just using GPS alone. GPS alone has humongous (huge) error of couple of meters and can suffer from multi-path reflections other sensors are needed to help it.
Here it's
(2) point. All and absolutely all sensors are needed and deliver non-replacable information. Those different sensors are not there just because someone wanted higher board costs but because they measure
completely different things required by autonomous system. You can't have one sensor not working and think something will compensate it, this won't happen. For example GPS does not know heading, only magnetometer knows. Revo has built-in magnetometer and it works if you put your board far from wires, or you have big copter (like in old days) where most wires that are twisted go far from the board. On <300mm builds this is no longer true. You need external magnetometer to use it. Built-in mag is still useful to determine correct mag rotation in GPS unit though. Not working Mag is usually cause of moving horizon when copter stands still.
Another sensors is barometer, it should also be well calibrated and altitude-hold function must be working properly, for autonomous flights using GPS. When you turn on GPS functionality, you must be sure, all sensors are functional as expected.
Problem is that most people come to this hobby, and assume that GPS alone gives good estimate, I think it might be related to smart-phones analogy. However, even smart-phones use sensors, gyro, accel, mag and wiresless network, wifi, nearby devices to improve accuracy of estimated position on the map. This is not just GPS alone.
Secondly, people have expectation that building DIY from not necessarily well picked components, should be easy, perhaps someone not knowing even what fail-safe modes settings are should be able to operate DIY copter. Definitely NOT, you really have to know what you are doing, read, learn and be responsible, not to cause more harm to other people in this hobby.
I hope this calms damn a bit topic which is in my opinion exaggerated. People here are not any commercial company giving support for their product, everyone here is friend, trying to help you when they have spare time. But it's your responsibility to learn how to assemble, tune, operate DIY copter. We can't force you to read instructions after all.
What I like about this hobby, is that I learn a lot, and I can come up with my own improvements, that's what DIY hobby is, right ? Tinkering, learning, experimenting. Lots of fun is spend on building, customizing and I think that's where this project stands up in contrast to more ready-to-fly solutions such as DJI. I have full respect to DJI pilots, their engineers and programmers as they have a really smart team, the only difference is that they're targeting different niche and cover just one type of pre-assembled always the same hardware.
