Mahu, you are such a dirty cheater.

j/k
Everyone I know uses the hull instead of the flying base.
Know however, that:
1. you only technically are supposed to use the hull if there is no base.
2. you are technically not allowed to remove the flying base in preference for the hull, as the hull is not a "base", and therefore you would be using a smaller base size (zero) than the one provided with the model.
Based walkers are the only vehicle that I can think of for which I would use the base for measurement purposes.