I live in Arizona and we've had some ridiculously high temperatures, so I haven't flown my P4 in 2/3 weeks. Last time I flew it was a couple days before the most recent firmware was released. Anyway, I updated the firmware tonight and decided to take it out for a 10 minute flight as I missed it. Immediately, I noticed something different. Pre-firmware update when the propellers spun up, they would spin up fast and almost sound like they would rev and then they would stay spinning in idle what seemed like a pretty hard idle. Today, however, it didn't do the rev-up and the idle was so slow and quiet. Normal? Part of the firmware update? Flight was otherwise normal. I'm guessing the idle was toned down maybe to preserve battery.