PivotTable and the charts containing the Data Labels are not fully supported by ODS format, of OpenOffice CalC. At least, MS Excel 2016 won't support them; as per the Microsoft's help-article about the differences between the ODS and XLSX formats.
That article has noted, that a Password-protected Sheet, shouldn't be saved in ODS. Presuming the same is true, for other open file formats; it might put off some Businesspersons.
It is easy to understand why JRE (Java) has to be installed, to make OpenOffice Base work. You need it if you wish to handle Databases. However, most of the users are better off staying away from installing Java on their machines. It has become safer; but the Database option should have been hidden in the Settings, speaking personally of course.
The User Interface could be improved, for aligning it with the modern Design Philosophies. The younger users might be seriously disappointed, because of the current User Interface.
The files can be saved in DOC, PPT, XLS, ODB, ODG, ODF formats; as a result, when you open them in MS Office, they are opened either in the Compatibility Mode, or the Protected View mode. I don't think, that my clients or employers are going to be okay, if such words appear in their Window header.
So, you might want to convert them into DOCX, PPTX, XLSX etc. before sharing those files with your network.
Also, keep a note for the OpenOffice version, and mostly it will be 32-bit for Windows PC, if I am not being incorrect. Why? Because then, you need to download the 32-bit JRE even if you are on a 64-bit system, for using OpenOffice Base (databases).
I wish if they improve it, in these aspects. Review collected by and hosted on G2.com.