I am still happily using my Lumix GX9 in a Nauticam housing. It mostly gets used recreationally in Scotland (lots of sea lochs), but has served me equally well in the tropics. I used to work in Antarctica as a marine biologist, used the camera with 7mm mitts no problems and I got some of those pictures published in dive magazines - full two-page spread of photos under ice in winter, so dark and really pushing the camera, but still publishable. The setup is a dream to take abroad, it all just goes in one carry on bag, which is admittedly a bit (very) heavy, but I've never had any problems. I use a Sony A7iii topside and have been considering an underwater Sony A7c setup, mostly because I dive some pretty dark environments and find doing wide angle at depth tricky if you want to get nice ambient water colours, I wouldn't push my GX9 camera past 2000 ISO, but luckily it's got good image stabilisation so I can usually manage. Realistically, given all the lenses and ports I currently own, I'm hoping for a GX10 with new tech and a Nauticam housing with a reasonable price...likely I'll be using my GX9 for a while yet!