Support for multiple concurrent file transfers over a single SFTP connection when supported by the server. OpenSsh and BitVise support multiple concurrent uploads, multiple concurrent downloads, and concurrent uploads and downloads at the same time; other servers may be less robust.
Up to a 50% speed increase for file transfers.
Introduced support for standard SSH compression and OpenSsh's "zlib@openssh.com" compression implementation.
Improved handling of invalid filename characters when transferring files from a non-Windows server to a windows client.