We have a new release candidate ready for testing (link below). You can flash this version in QGroundControl by choosing beta. The main changes since RC2 include robustness improvements for EKF2 and NuttX fixes.
This has been extensively test flow by our test crew in Tijuana. v1.6.0 has also been test flown on VTOL and fixed wing. However, we would like to encourage you to contribute to the testing.
This release requires a recent version of QGroundControl for the best user experience, so make sure to use a daily build until the QGC release is out (in the next days). The builds are available here:
I will add extensive release notes in a second post. We are editing them right now here.