Well, I took the plunge, and bought the new Cosmolite FL ... and it has survived long haul to the UK and back. The zip is protected by an outer layer which is good. The case itself is scuffed but intact, and it's probably a good idea to fill it to its absolute limit, as when I picked it up after one of the flights, one half was slightly pushed inside the other which looked odd. So the fuller it is, I guess the likelihood is that won't happen. Very happy with it though, and SO easy to push around, very smooth.