Howdy Drefish,
Alas I've been away working, so my planned trip to the Red Sea was put off, and the local beach I have here locally is utter rubbish for diving, let alone uw camera stuff.
I have had it in the pool - and I'll see if I can get in there again this weekend. But so far:
+ Major upgrade in stability, when I get the GH5 with IBIS I can see footage being silky smooth.
+ The top bar and tray, really make the rig strong.
+ Amazing detail and 'WYSWYG' on the screen
+ Lovely bright and colourful screen, compared to my Ninja2
+ Waveform and Zebras monitoring for ETTR
+ Focusing is spot on, can really see what is or isn't in focus
+ 10bit Prores 4k is a world apart from h264, I will never shoot in h264 again!
- Not ideal screen position - very close to you, but perhaps I just need to get used to that, but at the moment I'm holding it out in front more.
- Heavy
- As I'm recording in 10bit, I can't have the GH4's info displayed externally, so changing settings, I need to 'flip' the flame up to see the screen for changes for example to WB, ISO etc.