If you mainly use it for photography, I can tell you that the video look better on the P3A that the P3S. For some reason, on the P3S, the video has a "wavy" look to it, whereas the P3A is solid with no distortion. I know they both have the same Sony EXMOR senor...however, the P3A can shoot 1080p @ 60fps and the P3S only does 30fps @ 1080p (and 60fps at 720p).
Well, if you never go more than 1000 ft, out the box, the P3S should have been more than sufficient. I firmly believe that quality control plays a big factor in these drones. You'll see posts on this forum of people flying 6000+ ft with only a windsurfer mod, and then there's people like you that can't even go 1500 ft with a 3rd party mod to the controller. Most of us (you included) are only modifying the RC not the antennas on the bird itself. It may end up not being an issue with the ARGtek Range Extender, but the antennas in the bird. Sounds a little contradictory as to what I said earlier, but as I was typing this response it dawned on me that we're only doing 1/2 the modification. It could be as simple as the antenna cable in the bird isn't properly seated.
Looks at all the glue crap in my original controller: