I have been using Manager for over three years.
It is stable in that it does not crash, is fast to load, has small footprint and the best feature is that it is simple to use which is the main reason most people use it.
Yes it does have a fast release cycle, but most of the updates (which we never see) are minor updates (such as improving coding behind the scenes) and working towards adding new functionality.
I have found what works for me is to update Manager on my computer and then compare differences with my laptop using the old version when a Major release is brought out - i.e.when I see a release topic posted in the forum. In addition, I only update Manager when I see a new release out that I wish to take advantage of, so generally every four to six months I update the program. There is no need to update daily or even weekly.