Tried to set up synchronization in 5.5.0 and looked through all the configuration before doing so, seeing it all seeming ok i clicked start and it started the process. Within seconds I noticed rather then saying something like "download" it said "delete". It was deleting my server! Why? because the sync folder did not already have the files in it, it assumed that I wanted to sync an empty folder with my server, so good bye every single file. I caught it in time but would like to know the cache for WinSCP if possible, 2 files were not backed up and it will be a nightmare if I cannot get them.
This leads me to the feature request. When comparing if it sees and empty folder it should go into "idiot" mode and ask the user if they are sure they want to perform the action. Something like a dialog that tells the user "x files will be deleted, x files will be uploaded and x files will be modified". If I seen this the disaster would of been averted.