Silver

I like self checkouts, I like not having to talk to people. Just easier on my very autistic brain.

Still should be plenty of regular checkout lanes too.

I like the idea of self checkout. The practical reality is often quite bad … I’d rather deal with a cashier (cashiers in my country rarely do small talk, it’s a very rote interaction) than having to wait for an employee to deal with the self checkout’s weird issues.
This is why self scan is my favourite. Just scan stuff on your phone as you walk around, pack your bags ahead of time and the only time the staff need to get involved is age checking alcohol or painkillers, if there is some problem you had scanning something or if you get a random rescan request (which is admittedly horrible as it makes you feel like a criminal when they find the one item that didnt scan right). So much easier and faster than any of the other methods.
I’d rather not use phone apps …
Then use the provided scanning handset! Both are provided, just depends what you prefer.