I like the Weiss UI! It will be good to see the dark mode, but it's friendly for new players and have intuitive design!
The Wiess sports book looks interesting, it's a bit different from the others and I like it. I didn't bet much, I played more slots on this site. Definitely one of the more interesting crypto casinos, but the mandatory KYC is probably one of the things people don't like on this site.
Not all casinos are good even though they have a nice UI. So in the end, UI is not as important as it is important to be able to trust the casino itself.