I upgraded hoping for a fix on the GH5 play back resolution which it was but all my audio filters are now offline... So you may want to wait to finish current projects.
I used the combo for a long time... i shot this doc ( https://youtu.be/WvTHst-NOhc ) entirely on that set-up, and i loved and still think it's one of the best looking set-ups i've ever had. i really liked it but switched to the GH4 because i felt like it was difficult to lug everything everywhere and i was missing shots because it was just too much junk mounted. i had the odyssey and a zacuto viewer so i could see in bright sun. shooting now with 4/3 cameras i love how fast and nimble i am. i miss the part of looking at the robust footage on my computer but honestly once it's all said and done and on youtube and probably half the time viewed on an iPhone it really doesn't matter too much i feel.
I've taken my gear to the top of mountains working on a film about the Seven Summits in some of the most brutal conditions. The worst is the extreme cold/ windchill. I always make sure to keep my camera in the same temp as the air so it doesn't condense and then freeze. The batteries I keep next to my body in a waterproof bag and sleep with them at night. The workhorse has been the 5d Mark iii, but I have used the FS700 on the summit of Kilimanjaro and a Blackmagic Pocket Camera on Aconcagua (it failed to power up when the temps hit -30 but the 5d still worked like a charm). Keep the cam dry and the batteries warm seems to be my motto.
I actually just got back from an incredible trip climbing the highest mountain on the western hemisphere Aconcagua. Jimmy Chin is defiantly one of my heroes and I can't wait to see his film. For me the biggest challenges is not only climbing and being safe but when everyone else is resting your always setting up a camera for a time-lapse or filming an epic view. If you care here is the teaser from the trip; http://www.redtideproductions.com/Aconcagua