Good article, I have been using bitvise's product sftpc.exe which has very good logging giving me the ability to not only use the SSIS embedded start process task but I can start it with a logging exe to produce transfer log files for each file which are in turn emailed to distribution lists.

Within the Start process task I have setup two Expressions to set the Arguments and Executable.

Arguments - @[User::SFTPC_LOG_ARGS] + " " + @[User::SFTPC_LOG_FILE_PATH] + " " + @[User::SFTPC_LOCATION] + " " + @[User::UserName] + "@" + @[User::Destination] + ":" + @[User::Port] + " -pw=" + @[User::Password] + " " + @[User::MD5_BB] + " -cmd=" + @[User::Command]

Executable - @[User::SFTPC_LOG_LOCATION]