Solved my Problem

I use Aperture and have 3 managed libraries totalling 635 GB. I use Sync Folder Pro to make two copies of my working library every night (151 GB). My backup devcies are two NAS units 8TB each. Im able to sync over the (wired) network without any problems. Twice a week on different nights I sync the other two libraries to the NAS units (362 & 122 GB). Sync Folder Pro will read inside the Aperture Library Package and update/delete only the files that have changed. I routinely open the synced library in Aperture to verify that backup is "OK", and have never had a problem. Before discovering Sync Folder Pro it was a pain to try and keep backup copies, now I just schedule it for the middle of the night and forget it.

mdirvin about Sync Folders Pro