It is only sink when you sync everything including the kitchen sink.
I tried the demo a couple of years ago but I found it easier to back up what I wanted when I wanted manually at that time.
I just read,
"Actually keeping all of your files synced and up to date is quite a pain. If you were talking about two Macs my standard suggestion is ChronoSync." on
http://www.tuaw.com/2008/05/02/ask-tuaw-permissions-problems-html-email-quick-look-and-illus/ . The other day, I read a similar comment about ChronoSync. I don't think that there are that many apps out there that would do what we really want automatically.