Just got 3.2.1 and am very happy about the new synchronized browsing. This is a function that was sorely missing. Thanks a lot!
As to folder and folder tree synchronization, da chicken
posted on 2008-09-16 (see above):
Because of the limitations of FTP, FileZilla can only look at two things: file size and file date. Date is preferred, but you must enable Preserve timestamps from the Transfer menu. You can then transfer the files once to make sure the times are correct. Now you can enable directory comparison on the View menu.
I would be very happy with a very simple synchronization based only on file length. As long as the limitations are clear, I see no problem with this. FileZilla just has to tell the user that it cannot determine whether a file differs if it has the same length.
However, FileZilla could easily do more. For example, it could update a file also if the times differ by more than 24 h. It does not matter if it copies a few files that are not actually different.
Another solution would be to keep a simple local table of file CRCs and record all changes and deletions. Then FileZilla could upload all local changes to the server. Of course this works only if nobody else changes files on the server, but that is the most frequent case, probably covers 90% of all FileZilla use cases. Again this is perfect, as long as the user knows the limitation.
The point is that there is a wide range of options between perfection and nothing. The total lack of any synchronization is painful.