Personally I prefer to use DataPilot to program missions than Pix4DCapture.
DataPilot is more like the way you work with Mission Planner which is what I'm most used to. Even so I consider, speaking only of the features of programming surverys, could be improved with very simple things that would facilitate our work. That we can program it in the desktop computer and then pass it to the aircraft is very comfortable. Although in some update we have lost the functionality to do it wirelessly.
Pix4DCapture has had problems logging flights, essential if you have problems later, and some disconnection problems as commented by colleagues here. Having a third player in the equation in case of problems is not advisable since with DataPilot you can do the same, sometimes with a little more work, but eliminating another point of failure that may be the integration of the software with the H520 platform.
The stitching of images, is already a more difficult subject, to fill many threads