I also installed Brother's linux drivers and configured the scanner as a network scanner (it connects through wifi), and it works with gscan2pdf, except for 2 problems: 1) I couldn't get duplex scan to work (unlike in the ftp method) 2) the scanner options don't show up in gscan2pdf's scan dialog, so it just seems to use default settings. Now I can scan without touching my computer, and it doesn't depend on any driver or scanning software. There are 2 hardware buttons that you can map to different ftp profiles, so what I did was to setup an ftp server ( vsftpd) on my computer, and map one button to do color scans and the other button for black&white, and both upload the scan as a PDF file to my computer. I'll start with my favorite scanning method: you can configure the scanner to scan to an FTP server, with a pre-determined profile that you enter through a browser-based interface. I was very close to giving up and buying a Canon P-215, which I would be forced to use on a mac or windows machine but then I discovered the new Brother models ( ADS-1000W and ADS-1500W), which have official support for linux! I couldn't find any discussions of these on linux forums, but since the ads-1000w was on sale at amazon I decided to give it a chance. I was looking for a document scanner to digitize my piles of paper, and was very disappointed to see how many of the current models don't seem to be linux-compatible.
