Hmm, I use Create Synchronicity although my usage is simple manual file sync across desktop/laptop and backups.
Worth looking at to start with anyway
Further, the idea of a two way mirror... hmm very risky
From the Dev:
Edited by Chickenman - 8/12/13 at 6:03am
Many users have suggested that a two-ways mirror function would be a great addition to Create Synchronicity. It would probably be, but there are extra factors to be considered:
I must say I feel quite uncomfortable about two-way mirrors.
Indeed, Create Synchronicity was created and designed in the aim of building a rock-solid syncing application. When writing this application, my main concern has been to ensure maximum security. In this aim, I have put a set of preventive measures in place to avoid accidental deletions, which include the facts that the deletion-related functions are never called on the source side.
Implementing a two-ways mirror function would require violating this design principle. It would imply modifying critical parts of the application, which is of course feasible, but would introduce lots of risks. And after all, keeping backups, as well as syncing, is about providing you with security and ease-of-use.
I had a very painful experience myself with a two-ways mirror once, which basically deleted half of my files; hence my reluctance to implement a function which could potentially delete unsaved files.
Essentially, the way Create Synchronicity has been created is to avoid this, and the two-ways sync feature is thus unlikely to make it in Create Synchronicity; sorry!