Great article/review of the P4 written by Romeo Durscher, Director of Education at DJI. Was pointed it's direction by DJI-Ken on the official DJI forums. It goes quite a bit further in-depth than some of the others I've read so far. Highly recommend it if you're curious! Some real quality info in there. Phantom4 - Mark and Romeo's Aerial Adventures ... Please read the review itself that is linked above, but if you wish you can find below some paraphrased highlights that were of interest to me. If I should add anymore or something is in error you think please let me know! Major Points: Visual Positioning System has seen a hover deviation improvement, going from <+/- 1.5m to <+/- 0.3m. This also now works at up to 10m above the ground, an increase of 7m. Switch on left-front of the controller is now labeled as P-S-A on the P4 remote, as compared to P-F-A on the old P3 remote. "S" stands for "Sport" mode. Moving the switch to "S" will put you into the fast mode which will increase your maximum speed to around 45 mph and disable collision avoidance. With the removal of the "F" spot on the switch, different flights modes such as POI, Home Lock, TapFly, ActiveFly and etc are now accessed through the app. Field Of View (FOV) of the front optical sensors is vertical +/-15 degrees and horizontal +/-30 degrees. Which is the reason why it's deactivated in "Sport Mode": the Angle Of Attack (AOA) of the aircraft will commonly exceed those angles. In comparison, in normal mode the aircraft will never exceed 15 degrees pitch in regular flight. Threaded filters designed for the P3 will work on the P4. The new Pause Button is a feature allowing you to immediately put the Phantom 4 into "Pause" mode during autonomous flight. When flying in autonomous mode, like the new TapFly or ActiveTrack for example - the operator presses the Pause Button and the Phantom 4 will stop immediately and hover, waiting for the next command. Really great to have a quick stop function availabe directly on the remote. The Pause Button replaces the Play Button so to playback images and video you will have to use the app. Improved gimbal protection clip. It connects to the left and right bottom of the landing gear and goes around the lens and the camera/gimbal assembly, providing very good stability. TapFly Mode. TapFly is described as a cable-cam type of feature. When in TapFly mode you are shown an artificial horizon indicator on the screen and a speed slide bar (speed starts at 1m/s). Tapping anywhere on the screen will send the aircraft flying towards that location. In this mode, for the time being, the P4 will try to automatically and smoothly go above and over obstacles in its path while in this mode. If it cannot it will simply stop upon reaching said obstacle. Tapping above the horizon (as into the sky) will send the P4 out to its maximum selected distance and height (or to signal loss if no max distance is selected). The author says that eventually the aircraft will be able to find ways around obstacles as well. (I take this to mean a future firmware/software update). ActiveTrack Mode. Has several different tracking profiles such as "Person". You select your target by dragging a box around them on the screen. A profile is then automatically selected to that target denoted by a symbol in the top left of the selection box. In the reviewer's case it was a symbol of a person denoting that the person profile is being used. In this mode the aircaft will follow the subject. While following the subject the aircraft will avoid any obstacles seen by its forward facing sensors. From the author's wording it appears that if given enough time the drone will be able to slightly avoid obstacles while doing this but otherwise it will simply stop if it cannot avoid the obstacle. ActiveTrack & POI. One great feature of active track is the ability to do a point of interest rotation on a moving subject. In past aircraft such as the Phantom 3, point of interest was limited to a set stationary location. Now you are able to follow a tracked subject and smoothly rotate around them all while keeping pace. The speed of rotation is set by moving the right input stick. ActiveTrack Issues. Active track can lose track of a subject if the camera is facing directly towards the Sun, if there are long and dark shadows, if the subject is wearing clothing very similar to the background of the footage, and if the subject goes behind an object. In these cases though, active track has often been able to reacquire the subject automatically. Not always though. There is a lot more stuff found in the review itself and I highly recommend reading the linked review. There are many videos and pictures as well! I may add more later on.