At some point, the new schematic symbol library system will go online, and that will be a major change.
However, they did seem to be less likely to create extra bugs, and the new features seemed to work as expected.
I REALLY LIKE MY NIGHTLY. So much so that I did NOT even consider downloading and using the newest 4.x stable.
Old Nightlies are not maintained so they don't get more stable with age.It just happens that most of last years were well behaved.Once you know how to repair break downs and have sensible backup plans by all means use Nightlies, but they are not for people who are just trying KiCad for the first time and for those who depend on the package working NOW