I've reported a couple of bugs so far, with the biggest one being difficulty in downloading updates to apps in App Store. I initiate the update (doesn't matter if I select an individual app or use the "Select all" option) and the download status indicator appears as expected. But there's never any progress. I've had this happen on previous betas, and it was a mater of waiting, because the download WAS happening despite the lack of the status indicator changing.
This time around, it's a matter of apps not downloading at all for me. I've closed, force quit, and restarted the App Store, but this doesn't fix it. The only remedy I've found is to reboot the iPhone - after that, I can download updates without issue. Don't know what changes in-between that and the next time I have apps to update.
Anyway, that's the biggest thing I've noticed in my usage. The other stuff I've reported includes Facebook crashes (but really, is THAT a problem?), and a couple of instances of text that is cut off.
For context: I'm on an iPhone 7 and it's my daily driver.