Firmware v4.0.0-rc2 good to go? someone tried?
The -rc2 in the file name means Release Candidate 2. That means it is not fully tested and we are looking for people to test it. Flying a Release Candidate means you are risking your vehicle. Asking if it is good to go and has somebody else tried it is not a wise approach to a keeping healthy vehicle.
In general you should only be flying the release candidates if you are part of the testing team. If you want to be part of that team and are interested in testing specific features and issues we would love to have your help. Please join the discussion at https://discuss.ardupilot.org/t/copter-4-0-0-rc2-available-for-beta-testing/48851
We appreciate and we thank the people who accept the risks, make the test flights, and give feedback - either good or bad.