Nod,
your assumptions are mostly correct. The main principle is the following:
CintaNotes 1.0 uses a file system listener to monitor the data file change. Each time the file is externally modified, CintaNotes reloads it (I guess "reconnects and refreshes the view" will be more correct here: CN doesn't load the file into memory as a whole any more). And if you're curious, external modifications are differentiated from internal ones as follows: CintaNotes knows when last data modification was made and ignores data file change notifications which come within some grace period after that [currently 15 sec]. All notifications after that period are considered external.
So the data file gets locked only during writes, but not during reads. And CN doesn't wait till the next write for file reloading, so you're able to see the notes taken on other PC as soon as the data file gets synced.
This allows for synchronization of several PCs for one person, even when all CN instances remain running.
I think you already understand that this scheme is not reliable when two or more people use CN with synced data file simultaneously.
It is also important not to move from one PC to another too fast (i.e. faster than it takes DropBox to sync the data file on both ends). Otherwise the following can happen:
1) You take a note on PC-1.
2) CN-1 updates the database file.
3) Dropbox starts syncing the file.
4) Before sync is complete, you go to PC-2 and take a note.
5) CN-2 updates the (old) database file.
6) Dropbox registers a conflict and the file from CN-1 will be saved with "(conflicted PC-1 version)" suffix. Your note from step 1 won't be completely lost, but you will have to get it out of this "conflicted" file manually.
Plus, can you say more about “But it's best to put the backup folder outside (of DropBox) because of file version conflicts"
This is due to the fact that CN doesn't check if the backup file has been written externally. So CN-1 creates a backup, and CN-2 creates a backup before the backup from CN-1 is synced in. DropBox doesn't care and even if the files are identical, there still will be a conflict. Since this happens hourly, these conflicted files can pile up.
So by following this advice you save the disk space and also DropBox bandwidth.
Moreover, in 1.0 you will be able to specify the path to the data file in cintanotes.settings. This means that the best practice will be to place only the notebook data file in the DropBox folder. (I used to get frustrated that I couldn't have different font and window size CN settings on different DropBox-synced PCs, now it will be a no-issue).
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