The only appreciable difference I see a need for a border guard to physically inspect and stamp passports, which I suspect slows things down. I guess EITAS checks in the future too.
Once EES comes into effect the stamps may not be necessary anyway, but much like fusion, it's perpetually 6 months away.
Once EES comes into effect the stamps may not be necessary anyway, but much like fusion, it's perpetually 6 months away.