I use extended properties extensively in my own work as a developer.

I am loath to use them on other developer's work as a dba.

That's because when a script gets run that drops an oblect, the extended properties I added will be lost.

I'm not the only dba on the team, so I can't ensure that the extended properties are saved and restored after the item is created. Nor can I ensure that the developers add them to their source code.

Incidentally, extended properties are not included in the generated create scripts for all objects, i.e., views. That's particularly annoying to me as I like to include column definitions in the views for the data dictionary reports.