That's an unusual question?
Many of the people on here rave about the vast differences in the 3 and 4. If you have exactly the right conditions, and settings there may be a visible difference, but in reality, compared to work from a real camera, it is insignificant. I still have my 3A which does not have the infamous phantom 4 'fell out of the sky' feature. I have been quite happy with it for years. I never mess with it, never update anything and never submit the photos to National Geographic. Your mileage may vary.When I compare my phantom 4 pictures with my phantom 3 pictures I see no difference. I was hoping for better.
If you have a Phantom 4, it should produce very similar images to what your P3 did as their cameras are virtually identical.When I compare my phantom 4 pictures with my phantom 3 pictures I see no difference. I was hoping for better.
True, true, true, true.And the final criterion is how you like your pictures. If it's OK with you then nothing else matters. If not buy a P4P as they said.
But you must know that much depends on the setup of your camera that is exp.time, aperture, raw or jpeg for still photos and of course the resolution - P4P has 4K while P3A not. But even this is a handicap for P3 only if you need to publish Hi res pictures or videos. For net purposes 1080 standard is enough. Everything higher needs so much memory space and processor occupancy that it's almost impossible to deal with it.
And at last - you need a quality 4K monitor if you really want to get everything out of camera. It is funny if somebody think that he can watch 4K video on the phone.
So don't bother with your question too much if you're not a professional photographer or video maker.