I have since 10 april. No major UI changes exclude now bar, new widgets, I like new island next clock when you have opened in background YT, Music etc. New clock and battery icon. Rest is minor changes, most icons changed. Nothing else.
Better camera, better battery, even the screen is more vibrant a little bit. I know it doesn't sound ideal, but at least they are going to release it again when the bug is fixed, rather than customers having problems because of that bug. Probably the next step they should release a software update to fix the bug on those devices that already updated.
Looking like a release in may for the flip 5. Just be wary that if you didn't purchase direct from Samsung, you may have to wait for carrier customisation so can be a bit longer