[phippsytech]

This sound like it's more efficient - however... (and ignoring the US specific stuff)

Even in forms where I've designed this it breaks my flow as a user. I'm used to suburb state postcode order (I'm an Aussie). It's how we were taught to write the address in school. It's been a pattern for a long time, and the reversal of the fields slows my brain down.

IMHO The better user experience isn't changing the order of the fields. It's honouring auto-complete so the user doesn't have to enter this data in the first place.