Google has started rolling out the third developer preview of Android O which finalises the APIs of the OS. This is the second last developer preview release of the OS and squashes most of the bugs and stability issues reported in the previous two DP releases of the OS.
The DP3 release notes from Google still list quite a few bugs and issues including system performance slowing down, camera app being slow to launch, and more. Google will likely address these bugs by the time the final developer preview of the OS is released in July. As for the final release of Android O, it is expected to drop for compatible Pixel and Nexus devices, AOSP, and the ecosystem in Q3.
If you are in the Android beta program, you should receive an OTA update to the latest Developer Preview release within the next couple of days. And if you cannot wait for the OTA update to land, you can always go ahead and flash the factory image manually on your device.
If you have been holding out on flashing the Android O beta on your Nexus or Pixel due to stability issues, you can now safely jump on the bandwagon. While this release will not be free of bugs, it should not contain any deal breaking bugs as well. For developers, apart from the final APIs, the DP3 release of Android O also brings along with it the official SDK of the OS. Make sure to grab it from the official site and update your projects accordingly.