On the changes that have occurred in the new version, you can read on the official site . ')
The main changes, in my opinion, are:
New web-based UI (looks the same on all platforms);
pass the secret using the link (using HTTPS). When transferring a secret in a new way, you need to receive confirmation from the sender of the link. You can also set the expiration date and the number of uses of the link;
Now Sink can work through a proxy server;
integration into the context menu of the file manager (Windows Explorer, Finder);
Android version has acquired two modes of operation: simple (by default) and advanced.
Screenshots are made in ArchLinux (google-chrome), but on all other platforms the UI will look almost the same.
At the same time, BitTorrent has changed the interface for the Sync page:
UPD1: Windows XP and Server 2k3 is no longer supported, be careful, downgrade is not possible!Have to recreate the balls.