Enjoying Brasil at the moment, but the rain has been heavy in the South. Sampa, specifically in the Jardins area was especially torrential a day ago.
My Rimowa kit here consists of a Salsa Sports Case, Salsa Carry-on, and a Bolero Notebook. Zero problems in Rome, Brasilia, and Fortaleza: All dry and intact inside. I now see more Rimowa luggage in the airports here than a few months ago. No scuffs marks thus far either, and the carry-on has not had a problem in any of the overhead bins along the way.
I have no problems with the Salsa clamshell design. I divide shirts, underwear, and slacks in Rimowa bags of different colour. I simply lay either case down, remove what I want, zip them closed, and leave them in the closet. It just takes a few seconds.
Downside ? Try swimming laps in the rain. And I will need a new travel umbrella after this trip.