Symlinking and hardlinking both work very fine, just be careful with files permissions if your goal is to make the files downloadable from a webserver (and this is a very nice way to avoid redundancy and synchronization problems).
Tested extensively so I can assure you about this.
Just another note: it seems that symlinking a folder does not work (you cannot anyway hardlink a folder due to the nature of the Unix filesystem), but symlinking/hardlinking files work fine.
If someone try to symlinking a whole folder and get it to work then please share how you did!