I saw a P4 today at the RCX show, Orange County Fair Grounds, CA. The vendor let me check it out pretty thorough. They hadn't flown it either due not having an app, like everyone else. The quality looks really good, it's a step up from the P3 on the materials and finish. The plastic does feel more rigid and stronger, but we'll see. It's funny, the bird actually looks trimmer to me when handling it, because the view from the top is what you see the most when looking at it, and we all know it is more slim from the top view. It's only from the side view that it looks chubby, however when you see it in person next to the P3 from the side, the P4 looks way sleeker, more modern looking. It's actually a very nice integration of the gimbal, no rubber dampeners exposed or gimbal brackets anymore, which are homely looking. One thing that impressed me is the slots between the battery cells. I held the battery up to a light and you can see light through the battery array, which allows air passage for cooling. This should help to keep each cell more evenly cooled, versus P3 and Inspire where the 2 center cells are sandwiched in between others, and are more prone to getting hotter than the two side cells.. Pretty clever idea. There's a good sized fan in the belly of the drone near the battery. I've seen statement saying it can easily be heard when it powers up, before the motors are turned on. I'm guessing the cooling fan sucks air in from the bottom, pushing air UP through the battery somehow and over the circuit boards, then the air is exhausted through the motor arm vents, located on the bottom of the motor arms (versus on the sides with P3). It appears the air venturi of the props thrusting air downward aids to suck the air out of these 4 bottom vents. Also, pretty clever. I got to install and uninstall the props, and I definitely like it. It's much quicker, no tools required, and it definitely seems secure. This has proven reliable on Inspire, so I assume it will be the standard going forward. These differences are nice but subtle. Nothing huge, but it's clear the DJI engineers are doing a lot of homework for each new design. Kudos to those guys. I'm looking forward to flying one next week. What else have people noticed for subtle differences?