There's a lot to like in the Phantom 4. It shoots very-high-quality video that looks significantly sharper than what you get from the Phantom 3 and as good as the video from a 3DR Solo using a GoPro 4. The Phantom 4 is very easy to fly, even for novice users.
Longer battery life; Faster flight; Excellent image quality; App is straightforward and easy to use
Collision avoidance is not foolproof; Some modes disable collision avoidance; Flight modes are confusing; Occasionally catches sight of itself in video; Expensive