Adolfo,
>> > From a user perspective, I'm mostly interested in these qualities:
>> > - Good and stable API
>
>
> API stability can be tracked though proper versioning [1].
Given the developer knows how to use that correctly. Otherwise I agree.
Unfortunately, many developers either do not know, or choose to abuse the numbering conventions.
A recent example is PCL 1.7, which broke source compatibility with virtually every ROS package using it. I have no complaint about removing the ROS messages from PCL. That needed to be done.
But, the result should have been labelled 2.0, and there should have been a tick-tock migration path for it. They ignored all that: easier for the PCL developers, a major pain in the butt for everyone using it with ROS.