With the Mavic you will get twice the resolution when shooting panorama's as with the Phantom, if you use the same camera point. The reason for this is the difference in focal length. the Mavic's focal length is 1.4 times longer then the P3/4. So for a given area you have to make 1.4hor * 1.4vert =1.96 times as much images as with the P3/4, which doubles the resolution. Off course you can fly nearer to a certain object with the Phantom but that will change you perspective. It all depends on your subject of choice of whether this will be acceptable.