Today, Apple released a new round of developer betas, introducing beta 4 of iOS 11, macOS 10.13 High Sierra, watchOS 4, and tvOS 11. We're just about reaching the mid-point in the development cycle of these major updates, so they should be getting more stable.
iOS 11 is now on build 15A5327g, and while it resolves a number of issues, some third-party apps might not work still, such as DirecTV, MobileIron Mobile@Work, Tweetbot, and Square Cash. There are also some new issues, such as that an app may crash if you tap the AirPlay button while a video isn't full screen.
In macOS High Sierra build 17A315i, Apple still hasn't fixed the issue preventing users with HDDs only, 3TB Fusion drives with BootCamp, and the mid-2012 Mac Pro from upgrading to the Apple File System (APFS). Also, encrypted APFS partitions can't be decrypted, as that's a feature that will be added in a later build.
watchOS 4 build 15R5331g fixes a number of issues, but the known issues include the Watch not backing up unless it's unpaired from your phone (in other words, if you use the reset function on the Watch, it won't back up). tvOS 11 build 15J5333f, however, doesn't seem to have many showstopping known issues, probably because it doesn't really add any new front-facing features.
Of course, there are long lists of known and resolved issues for each of these updates; these are just a few that caught our eye. You can find the full changelogs over at Apple Developer.
There were a few other developer betas released as well. As usual, there's a new Xcode build that coincides with the OS updates, along with macOS Server 5.4, Classroom 2.1, and Apple Configurator 2.5.
If you're waiting on the public beta for iOS, macOS, or tvOS, you should see it within a couple of days. Of course, there's no public beta for watchOS.