Travel size does matter!
And that is why I decided to buy the OM D
I can pack everything in a small Backpack ( om-d + nauticam housing + Oly 12-50 zoom and macro port, Sea & Sea YS-D1 dual strobes with arms + Sola 800 focus light and 13” Laptop and I think that I still have more room for the pany 8mm and 4”domeport.( My next purchase )
I use the Temba shootout rolling backpack medium size.
Any decision you make will be the right one, the two cameras are very good