Not sure if you are still exploring manager for potential use or are already a user, but Manager seems to be developed using Agile processes which means continuous development with very frequent feature updates, quick bug-fixes, etc. but without a clearly defined roadmap. All those elements that made Agile application development popular and most used (search Google). Users of such applications benefit from the interactions with the developer via this forum where bugs are posted, ideas shared, etc. that help shape the application to the benefit of the users. Obviously, it is human, and we like anyone else are sometimes very frustrated with the loss of some features without a clear replacement. However, over time it is also clear that eventually these lead to better products. This waiting can be very frustrating and also some directions taken are found to be a dead end and then new ones get implemented leaving users in limbo. But we like it despite these flaws.
If, as you indicate, would like perceived stability, and feel more confident using an application where updates are few and are announced well in advance with only bug-fixes being made until the next version then Manager will not suit you.