With the exception of my ARC AAA Le and Photon II I only belt carry my lights. Even the US can be belt carried though I wouldn't advise it for difficult terrain. Blackhawk makes a superb holster for the M6 which gives surprisingly comfortable carry.
As a result, scratching and damage of any kind has become a non issue. All my lights look new, almost as pristine as the day I bought them.
For belt carry when dressed for work or formally, even a standard sized 2x123 light won't show unless you've got a pot belly that's already straining the buttons on your suit jacket.
That said, I still may slip an E2 or Inova X5 into my back pocket for backup.
Brightnorm