Aperture provides all the RAW conversion, image adjustment and DAM facilities in one application.
What are you doing to you image files outside of Aperture that would require you to synchronise updates to the items you have imported into Aperture?
Thanks to both for your replies. I guess there is no simple solution to my problem with the current version of Aperture.
Mark, what I mean is that if import "folders as projects" one day, and later want to import photos taken with a different camera the same day, that hadn't been downloaded yet. For example I don't download photos from my P&S every day, and when I do Photo Mechanic will put some of the pictures in a folder that has already been imported to Aperture. I still want all my photos taken on a certain day to show in the same project for that day. I will get the same problem if I download and import photos twice on the same day.