None of the above for me esp. when running. As others have mentioned, the ZF encourages good (and uptempo) running form with emphasis on forefoot/midfoot strike to hit the sweet spot aka plate for optimal energy return.
Those with "sensitive" or finicky feet might find the sensation of feeling those air units ("bumps" and ridges and all) through the new thin flexible midsole a bit annoying to uncomfortable. Esp when running, since there is no foam. There is a lot of wiggle room in the forefoot. Might just be a...