I don't really have a whole hell of a lot to add to the discussion here, but forums like this self select for people with problems so I thought I'd post a positive first experience. I just flew the P4 today for the first time... and it was super impressive. I actually got the P4 as a "trainer" to help get familiar with DJI terminology and technology in anticipation of the M600 we have coming. It's been awhile since I've flown anything DJI and I have to admit I'm pretty blown away. (I've been flying DIY pixhawk based builds for years - and recently the 3DR Solo for fun) This DJI Go app is great - and not just for flying. Hell, I updated firmware in the field. Worked like a charm. All the instructions were built right into the App. Phew. This is going to be a lot easier than I thought. I did have one hitch after the firmware update. My SD card is being reported as invalid now. But I assume I just need to reformat. Not surprising really. I'm sure the update process makes use of the SD card.