Ok, as I had taken the plunge and downloaded (as indicated in my previous post) and made sure at least Samsung Pay would work, I am now running the UI6 Beta on my UK S23 Ultra
First impressions, nice.... It's slick, no apparent issues so far, like the new notifications UI and also the Quick Settings UI
I know many will wonder about apps and how they perform under UI6 Beta so here are my list of WORKING apps
Monzo
Santander
Virgin Money (Business)
Curve
Google Pay (despite it saying it would not work with the Beta)
Samsung Pay
Outlook
Whatsapp
Galaxy Wear / Galaxy Watch
Only been installed for a couple of hours so cannot comment on battery life yet, but it's very cool to the touch, no heat issues as yet
If there apps that anyone might be concerned about, that I haven't listed (and that I may have) happy to try and report