Ok i have two Mavics as i have mentioned before all i can say now is they both act in very different ways on different firmwares.
one i bought in Russia in January and one was bought in Thailand in February
Russian Mavic has had every upgrade and flown 120 miles so far and and 80 flights, 4 hours of that has been on 0600 and it has always on every upgrade flown fine. apart from a noticable range drop since 0400 which only happens in the UK. In Thailand i was getting 5 kilos with signal still sitting fine at 3 bars. i had every confidence in 0600 on this Mavic and i always just press ignore when it says update NFZ zones. I really do have no problems with it flying ANYWHERE.
Thai Mavic was on 0500 and i could not update it in Thailand as we had a full island power loss with no cell or wifi (happens a lot which is why i carry a lot of batteries over there).along with car chargers and the power bank adaptor.
Anyway i left my Russian Mavic over there (along with the sd card with all my footage arghhhhhhhhhhh now gotta get it posted back here). i brought the Thai one home and updated it here to 0600
it flies like a heap of crap, so i downgraded to 0400.
stabillity is not as precise i think as the Russian Mav on 0600 although today and yesterday were a little too high wind wise to really say for sure. what i can say is she flew far smoother than on 0600 when i was actually flying her and those NFZ warnings etc on controller are gone. (i never ever get them on my other Mavic even on 0600)
when i did the upgrade here to 0600 i noticed that the option to ignore updating the NFZ is not there anymore and the GEO button was missing. The NFZ on the RC was annoying beyond belief, again i don't get that on 0600 on the one now in Thailand.
i took Bunnys advice and deleted the app as even after downgrading to 0400 i had no GEO button and was concerned the NFZ **** would still be active.
after reinstalling the app i had the AC turned on in the garden and A yellow NFZ warning came up but the GEO button was back (thanks bunny) and was defaulted as on.
Switching it off sent away the warnings and also the high wind warnings i get in low winds are also gone, as today was very windy, enough that i let her hover at 5 metres and watched her struggle like mad to hold position in the gusts no flying day today as i hate fighting winds.
i am flying both on the latest go 4 App with no difficulties. IOS latest and IPHONE7 plus, i use the same phone and app for both AC.
Two Mavics two very different personal feelings on each one having tried every software on one RC and two on another.
One fly's fantastic on 0600, and one does not give me the same confidence, but on 0400 i have that confidence back in the second Mavic
i am sorry i cant explain the technicalities of the differences, i fly and try to feel how they fly but i cant put those feelings into words to explain why each gives me confidence on one firmware but not another. its like driving a car and you feeling what it does with each input of the wheel or stick and the vibrations that come back to you telling you what is going on.
you drive through feeling and the Mavic is like that for me i try to feel and not just see what is happening with every input on the sticks.
all i can conclude is you need to switch around right now and play with all the upgrades and downgrades and find the best one you can, while you can and then stay right with that unless there is 100 percent conclusive proof that DJI have got one right and that this NFZ rubbish is not going to shut us all done in the future.
They already give a warning if anyone actually read it that when u upgrade the NFZ you are allowing DJI to take control of where you fly.
i will be keeping both drones exactly as they are right now one on 0600 one on 0400.
After reinstalling the app i also did not get the fixed wing option back. As i don't have much time i have not had a chance to do anything except re set all my settings and calibrate the AC compass.
I may now also consider switching to a seperate phone dedicated to flying each drone as i have a spare brand new iphone 6s sitting in a box in Thailand with only DJI go 4 downloaded on it.