Hi,
Yes, 1.8.1 is final.
The upgrade guide is available within the Update checker editor window that is launched when you installed the package from the Asset store.
The upgrade mainly affects new sets of actions that where previously available on the wiki and Ecosystem, now they are officialy distributed. This should not change or alter any of your existing projects, so the guide is really about cleaning up your project, however, since the guid are kept, even without cleaning, up things should go smoothly.
There is no know incompatibilities as far as I know.
Let us know if there is some hickups, we'll assits.
Always backup before upgrading is the most important part of a safe transition
Bye,
Jean
Bye,
Jean