Our use is similar to that of Glenn. To provide some context:
If we want to release an artifact to production, we tag it in our SCM and let Jenkins build it, Jenkins then copies the artifact to a different location so we can download it at a later time (even if the workspace is cleared). The copy is done via a symlink created in the workspace by our build script (soft link on Linux) to a folder outside the workspace on disk.
When we want to deploy the artifact we can simply download it via een link like: /view/assets/job/assets-BootstrapPortlet/ws/RELEASES/1.0.2/BootstrapPortletEAR.ear
The _RELEASES_ folder __ is a symlink. So we basically use Jenkins as a file server just like Glenn.
We do not use symlinks in the userContent folder, but we do use it in the job workspace.