Hi djaevla2,
I've been looking at this as well. It's how CMIS-Sync current works (from what I've also experienced). You are correct in that CMIS-Sync simply overwrites the files. AlfrescoSync on the other hand does indeed update the files' version number (minor version number only). However, I've also noticed that it doesn't allow me to place version "Comments."
What's nice about CMIS-Sync over AlfrescoSync is that it allows me to sync ANY folder on the system where as AlfrescoSync only allows "Site" folders.
What I think would be absolutely fantastic is if:
1. Sync files from any folder/site or even specific folder within a site (ex. if there's a 30-gig video file in a project that the video guy is editing, I don't want to download 30 gigs every time the guy clicks "save").
2. Set sync time frequency (check every 5sec, 30sec, 1min, etc - like CMIS-Sync allows)
3. Be able to right-click and say "Check-Out" so that it locks the file on the server (Like Adobe Drive CC does)
4. Allow me to delay upward-sync until I "commit" - this way I'm not upping the minor-version number every time I click "save"
It's still beta so I have hopes.