I generally prefer Samba over FTP, as it gives a better experience by allowing user to access the files as if they're still on local disk. And, unlike FTP, media files can be played directly from Samba. But, one might still need a FTP server as it offers better performance over Samba.
If the router has at least 8MB flash ROM and happens to run DD-WRT MEGA build, it is very likely there is a proftpd FTP server built in.
If the router has at least 8MB flash ROM and happens to run DD-WRT MEGA build, it is very likely there is a proftpd FTP server built in.
So why install vsftpd? The main reason is its size. The proftpd is 500KB while vsftpd is only 100KB! This makes it perfect for embedded systems. Also, vsftpd is easy to use and setup.