I'll just add that I'm going through a similar experience. Upgraded from an I1 to and
I2 about a month ago (purchased through Florida Drone Supply, with incredible pre sale support/advice from Michael, Jim, and Jenelle there). By pure fluke, my CrystalSky Ultra started flaking out during my initial
I2 flights. Since it had been fine with the I1 initially blamed the
I2. But then it became clear that the problem was my CSU. It has since died, and DJI is replacing it at no charge. In the meantime, I tried using my iPad Mini 3, which I had been using with no problem for my I1 until I got the CSU. The Go4 App running on the iPad Mini 3 seemed to work fine for a bit, but would then mysteriously drop connection to the RC (always at an inopportune moment) and I'd have to unplug and reinsert the USB cable in order to use the app again. Suspecting that the iPad Mini 3 did not have the cpu power to run the Go4 app (and discussing this with Jim at Florida Drone Supply), I tried flying the
I2 with the Go4 app running on my iPhone X and it worked without a hitch; no dropped connections, no video lag, all good except for the relatively tiny and dark screen compared to the CSU I'm now used to. So I'm looking forward to getting my CSU back, but will use the iPhone X as my backup for now. Considering an iPad Pro per Jim's advice.