I spent Friday doing firmware updates and IMU calibration, then took a trip to the Apple store on Sat morning for more batteries (1 hour away). I finally got around to flying the P4 Saturday afternoon. Here's my experience - The bird gave me both GPS and IMU errors on the status bar during warm up. I wasn't worried about the GPS error so much as it could have just been me blocking the signal, initially. After a fairly long warm up cycle the IMU and GPS errors both went away and it said OK to fly. I launched and flew the bird in P mode with sensors active. I was flying in 20-25 mph gusts and while the bird seemed more sluggish than my P3 with the stick buried (to be expected) it still managed to hold a solid 17-18 mph avg in all directions and felt more stable overall. I actually found that the max speed in P mode was preferable for my overflight footage, not too fast or too slow... just peg that stick and go. I flew around and got the shots I wanted at the lighthouse and was surprised to see that I still had over 60% battery left. It felt like I would probably be at or below 50% by this time if I had been flying the P3 in the same fashion. I can not say that with scientific certainty, as I still have to go back and review the logs to see how long I was actually up there. I then took a drive to the beach to do some more recording. Same odd start up behavior, IMU and GPS errors during warm up... never saw this on my P3 (on second thought, perhaps I did once or twice out of around 50+ flights). After launching, the first thing I noticed was that the video downlink was very choppy in a solid rhythm, it was annoying as hell but I just decided to live with it rather than fiddle with the channels and there were a lot of cottages nearby so it could have been some strong wifi interference contributing to the problem. After getting the shots I wanted I did a hand catch and packed her up for the drive home. Upon reviewing the footage and photos, which I found for the most part to be excellent, I was very sad to see that my lens was slightly decentered. The right side of the frame had a blur covering about 10% of the horizontal span. This was frustrating because the actual quality of the 4K footage was far superior overall to my P3 Pro. With settings at -1 sharpness, D-Log and 3D noise reduction turned off I was seeing nice, clean images without any significant artifacting or aliasing. The lens also showed significantly better sharpness than my P3 Pro. I bit the bullet and drove back to the Apple store, and they did a straight up exchange no questions asked (I bought the bird through Apple online). After unpacking the new bird and doing firmware updates I took it outside for some test shots. Lens looks great as far as I can tell. I'm very pleased in that regard actually, this is a much better lens than my P3 Pro - lower distortion, CA and respectably sharp for such a wide angle. I plan to skip the IMU cal this time around and just do a compass calibration and see how things go with the new bird. I'm not sure I'm sold on doing an IMU calibration at this point when no errors are even being reported. I'll post a link to my footage later this evening so folks can see the edge softness from my original P4.