No argument from me there, the aur is not very well made. On arch I do have some issues with how the aur is operated along with the behavior of arch maintainers. Not to the point I'd state using the distro is a bad choice though, as quite a few are minor, disagreements on tech philosophy, or currently being addressed.
My issue with manjaro is their continual incompetence while most of the time doing nothing to stop the issue from recurring. Most of the problems I have seen manjaro go through are repeated. They don't learn. Their issues aren't just structural but a culture the company holds onto.