The Brother DS-640 provides quality, portability, and usability in spades, with speed being its only relative weak point. Unless you're scanning 10+ page documents on a daily basis, chances are the Brother DS-640 will provide more than you need at a reasonable price.
The Brother DS-640 provides some of the best scan quality per dollar of any of the models we've tested. It often matches the quality of the expensive large office-focused models at a fraction of the price.
The PDFs I created came out looking nearly identical to the originals for general text scans. Even the ink on receipts, which can be problematic for scanners, didn't pose any problem for the DS-640.
The color scans I created in our testing looked fantastic. The colors were accurate and vibrant, and the resolution remained crystal clear. I was more than satisfied with the color documents I scanned with this model.
Photo scans came out similarly high quality, although the Brother DS-640 can't match the quality of a flatbed scanner when it comes to photos. You may not want to feed a treasured old photo through it, but it can get the job done in a pinch.
The Brother DS-640 isn't particularly fast, but that's because it has neither duplex scanning nor a document feeder. However, it's more than serviceable for documents less than ten pages.
In our tests, the Brother DS-640 took 26 seconds to scan a single color page at 600 dpi (a very high resolution). This is a respectable speed, but it's worth mentioning that half of the competing products I tested can scan a page in 20 seconds or less.
Longer, duplex documents are where things get a bit slow. Since you have to manually feed each page into the scanner, scan times for longer documents add up. Additionally, this scanner can only scan one side of a sheet at a time, so double-sided pages have to be fed through twice to scan both sides, doubling the amount of time and effort you have to put in.
In our tests, scanning a 10-page duplex black and white document (that's five sheets with text on both sides of each sheet) took 7 minutes and 10 seconds. In comparison, scanners that can scan both sides of the sheet at once easily accomplish the same task in under a minute. This difference in time isn't terrible if you only scan a few 10-page documents a week, but if that's a regular occurrence, then the extra minutes can add up.
In general, I liked the software associated with the Brother DS-640. I found its installation and operation to be straightforward and reliable on both Macs and PCs.
Perhaps most importantly, the included optical character recognition (OCR) software for both PCs and Macs proved to be more than capable in our tests. It consistently converted text pages into text-searchable PDFs without conspicuous errors.
The Brother weighs in at just over a pound, can be powered by a USB port, and features smooth paper feeding. It doesn't get much easier than that. The only place it gets bogged down is when scanning longer documents. Unfortunately, the lack of duplex scanning and an automatic document feeder makes scanning long documents a chore.
The Brother DS-640 is, in our opinion, the perfect solution for those that need high-quality scans but who don't tend to scan super long (10+ page) documents all that frequently. If this sounds like you, then I highly recommend making this the newest addition to your home or office workspace.
