[nyreed]

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.

[jpatt]

Right, from this article: https://www.nytimes.com/2023/01/27/world/europe/eurostar-bre...

The main difference is that pre-2021 UK travellers simply had to show travel documents whereas now they have to get them stamped.

On the surface, it isn't clear to me why that makes much of a difference in service time, but the CEO of Eurostar pointed a finger to these changes in January: https://www.bbc.com/news/business-64390979, claiming their trains carry 30% fewer passengers due to station bottlenecks.

And yes, they claim the EES checks should help speed this bottleneck.