This is truly a workhorse machine. We bought this scanner in December 2013 for scanning more than three shelf-meters of university notes, and countless magazines at home. Last time I checked the sheet counter in the ScanSnap manager the counter was at 66 899 scanned sheets (already a year and a half ago at the time when I write this review). The weight of the papers we have scanned is already over 200 kg. Scanning with this scanner is really easy as it scans both sides of the paper at one go, and the scanner detects overlapping pages / paper jams, and warns the user clearly when that happens. Solving the problems is simple and continuing the scan is fast. In addition the unit is really small when not in use and the paper trays are folded in.
We have scanned through a huge amount of hand-written notes that were made using pencils on a quite soft paper. Even with this kind of material the only problems we encountered was that the graphite from the papers slowly collected on the rollers during scanning, so that every now and then we needed to while the rollers clean as otherwise the scans had graphite roller marks on them. Our scanner came with OCR software (when bought in 2013) that works really well with the scanner software when scanning any material that is written in English. For Finnish there was no OCR selection available, which is a not big problem for us.
Anything larger that A4 we have manually cut to the size that the scanner accepts, which is not a problem, but just a notice to whoever is considering buying the unit. On the other hand, anything that has been A4 width, but much longer than normal A4 paper, we have successfully scanned with this scanner in one go. We have only used the carrier sheets a few times when scanning something larger than A4 paper.
The only maintenance we have needed to do with this scanner this far has been to clean the rollers (as mentioned above), and wiping / dusting the scanner's insides to get rid of dust and paper residue. Without removing this paper dust we noticed that the scans might have streaks in the resulting PDFs, as the dust is blocking part of the scanner head's surface. We have used this scanner with Windows 7. According to the ScanSnap manager, the rollers should be good for 200 000 sheets, so we still have plenty scanning headroom left!