For me never chambered.
When I carry-which is often-I do so because I do not want to be in a situation where I really wished I had a weapon but none was available. To me, the risks associated with a chambered round in a carry weapon far outweigh the benefits. To get mathematical, the risk of a chambered weapon multiplied by the large amount of time the weapon is carried is significantly more than the large downside to not being able to deploy quickly multiplied by the very small chance my carry weapon will ever need to be deployed.