Yes, it is. Once a distro is released, it is stable to use. There is no automatic updates/upgrades, so if one is worried about any breakage, one should not update manually. By experience, I can say that usually any Ubuntu release is stable. More than a decade, I use only the development releases (now 19.04), usually don’t have a problem with daily updates. If, by chance, any problem happens, the next upgrade would cover that.
It is pretty easy and quick to install any Ubuntu derivative, and, if you keep your Home in another partition, none of your data would get lost, if, by chance, your installation gets bricked. It usually doesn’t.
Once, the new 19.04 is released upgrade to it using the system upgrader.