If you have a Windows environment with server side profiles, you still have a local user profile, which is synchronized with the server during startup and shutdown. It takes the more time the more data is stored in the profile. Thus, it is helpfull to move NetBeans user dir (and cache dir) to a location outside the user profile. I suggested to let the user choose during installation and / or persist these settings in a way it can be re-used by later NetBeans versions.
Here a short excerpt of NetCat status report #7:
If you have strong opinion on requirement to set cache and user directories during installation, please add your comment to Michael Müller‘s #221351.
If you second this sugestion, please feel free to add your comment or simply vote for it.