If your key scanning demand is scanning documents on daily life – specifically these longer than double pages – you nearly need a document-centric scanner supported with the sheet feeder. Getting to open the flatbed lid and put a page in place is the chore, but getting to repeat the process many times for a 10-page document is tiresome. Other sheet-fed scanners might even tackle deep originals like ID cards.
If you will basically be scanning double pages for a while, the manual sheet feeder is perhaps all you want, or you could obtain it just fine with the scanner attribute on the all-in-one printer. If you will be scanning long documents every day, however, you will need the auto document feeder which might scan a whole stack of pages unattended. Stick with the ADF capacity up to the pages in the particular document you want to scan. If you rarely get a document that is more pages than the ADF capacity, you might add a lot of pages through the scan as the feeder processes them.