the way i understand it to work is more like–
open a previously saved file from dropbox and draw a line (or something to put it in an edited state)… after a few minutes, it will autosave and the save is going to the .3dm you have opened… dropbox notices the change and syncs… the file itself is continuously changing on mac… likewise, dropbox is continuously syncing… then when you do a Revert, it does a final save/sync with all of this sessions actions undone.
there are a few problematic things that can be brought up about this but from a consumer pov, i suppose one major thing to realize is if you’re using tethered data on one or more of the computers… if you’re modeling while tethered, you may be unknowingly using cellular data… disconnect after getting latest version and reconnect upon saving so it only syncs that one time.
i think dropbox (and others) are aware of problems in cloud type collaborations or multi machine workflows… here’s a thread from a couple of weeks ago which relates to this thread
also.
something that will sometimes happen to me which i haven’t really looked into is i’ll end up with new files in dropbox named such as:
HCouture_GamingTable_Shop (Jeff’s MacBook Pro’s conflicted copy 2015-08-19).3dm
instead of looking into the exact cause of that or even figuring out what state the files are in when it happens… i just try to prevent having the same file opened on two computers at once… as well as try to be a bit more clean with the workflow (not leaving files open when i leave the desktop etc (which is how this has typically happened for me… model on the desktop… go somewhere… open the file on the laptop… the file is now open on two computers…) so i just try to prevent that.