1. Versioning 2. Ability to use own Amazon S3 bucket for file storage, so your NAS/Server will store files locally AND on S3 which results in higher download speeds over the internet. However, an always-on device is still needed. 3. Some kind of defining owning user and owning group on linux machines. In my case, I would like to sync data from more than one users on my linux server. Each one got it's own secret and directory, but since the BT Sync application runs as root, all files are owned by root. 4. Speed limitation only for external (internet) transfers. 5. Web UI for File Management.