Global accessibility over O365 increased the collaboration within the organization.
I have used it for more than 11 years.
I have not encountered any stability issues, as such.
There were scalability issues with SP 2013, but MS made some improvements in SP 2016.
Technical support from MS is great, especially in the cloud area.
We were previously using a custom solution that was hard to maintain and there was also lack of user adoption. With SP, we were able to see great improvement in those areas.
Initial setup was straightforward.
Go for O365 plans that have different pricing as per business needs.
For enterprise global collaboration, DMS, and ECM needs, this is the right platform.