One bag and three backpacks ready all the time.
Bag with Leica stuff at 5kg, Nikon backpack at 15kg, 4x5 backpack at 13kg (trying to keep the weight down on this one) and 8x10 backpack at 30kg (that includes tripod).
I do not acknowledge GAS, but I am afraid it is getting harder to persuade my friends that I am not afflicted.