Very impressive performance with the antenna mod. It looks like a clean installation too. Very nice. But I have a couple of questions, and also the same concerns as mentioned by solentlife.
Questions: Did you have the RC in a fixed position for that entire flight? Or was it hand held for the entire flight? I noticed that your control signal levels varied nicely throughout the flight; not too many variations or extremes; it just slowly dropped down from start to finish as range increased. I was wondering how difficult it might be to keep the RC pointed correctly over that long distance to maintain such nice signal performance.
Concerns: Like solentlife, I have noticed that since the latest firmware update to 1.8.10 that my P3S range performance is more erratic. With the new firmware, my impression is that the signal seems fine one minute at a solid 4 or 5 white bars and then drops down to three bars and then just 1 or 2 red bars, in a matter a few seconds, and within just 100 feet of range the RTH kicks in. I noticed a similar phenomenon in solentilife's video. I am not sure this has anything to do with the firmware, but it sure seems suspicious.