I bought the black3 last year a week later the black3+ came out, was a pissed about that ... reason now why I am not going to buy a 400F5.6, as after years a new one has to be coming soon.
Great for video ... very poor for stills, unless you just want them for the computer @72ppi, very poor images to print.
Love the remote feature, I got some pretty good video of a small Azure Kingfisher not long ago. I was watching what branches he was landing on, I set up the camera on the branches about a foot away and crept back watching and waiting for him to fly up the creek, started the video and watched on my smart phone as he sat a foot away doing his stuff.
The Gopro video package is easy to use also, but I still tend to use Prem Pro to edit.
Sound is also very poor, so an external mike is a must out of water.