The trouble with making statements such as we always take off with a particular config is that another operator may have completely different ways of operating the same aircraft.
Hetfield mentions that the majority of his take-offs in an A300 are slat only yet in my airline with the same aircraft we usually use flap 15 or sometimes 20.Both airlines have decided to use whichever is the best config for their route structure and flex policy.
Unless you have that airlines takeoff performance charts in front of you how can you ever tell what is the correct config on the day or whether the correct config is set?
If I am going to do a slat only take-off I will brief the cabin crew as the ground roll is usually much longer than normal.We only do these in BAH on hot days/nights.