I got my ScanSnap 2 weeks ago and have now scanned about 7,000 pages of docs. Although I feel it's a flawed product, I think it's still the best available that I've found.
GOOD: * The hardware is really good at what it does: wicked fast, solid quality scanning. I can easily tear through 300-500 pages an evening.
* The hardware workflow deals efficiently with common problems, most notably, reliably detecting & helping you correct when a page misfeeds.
* It folds up into a small footprint on your desk.
NOT GOOD: * Hardware build quality feels really cheap for a $450 device. Most notably, the paper feed gears are all plastic. Mine already broke in just the first 10 days requiring complete replacement of the scanner.
* It's marketed as allowing up to 50 pages in the sheet feeder, my experience is that it typically can't feed paper unless you go down to 15-20. When I try with more, it makes a horrible noise and jams up. (I'm pretty sure this is what broke the plastic gear.)
Finally, the mediocre software. Speaking as a usability engineer who has also worked in the Mac OS team at Apple, the software interface is remarkably disappointing, especially for a Mac OS app. Saddeningly, most of the kinds of problems I see are ones that could have been cumulatively fixed in just a few man-weeks of a good designer & engineer's time. Here's just a smattering:
* After the first two pages that you scan, the window focus returns to the scan progress dialog. In other words, if you start a scan and go do something else (like surfing the web), the first time you press the space bar or return key, your scan job is aborted without undo, since you've pushed the "Stop" button unwittingly.
* File names can't be saved if you use characters prohibited on Windows (but not Mac). Worse, when you enter the name and it gives you an error (which gives factually incorrect criteria for what characters you can and can't type -- it keeps telling me I can't enter characters that I know I didn't), you lose the entire file name you chose and have to re-create it from scratch.
* The user interface text was clearly written by a non-native English speaker lacking usability or user assistance experience. Buttons and labels frequently even fail to conform to Apple's own naming guidelines. Even though the concepts behind the software are simple, it's often necessary to read the user manual to understand what different functions actually do, because the text labels are so poorly crafted, and rarely relate to the user task at hand. The error messages sometimes are just unbelievable -- I've worked on the design and creation of consumer software for 16 years and I've *never* seen anything this sloppy.
* There's so much low-hanging fruit that could make the software great: why can't it automatically propose a file name based on the first few words of a scan? Why can't the OCR take place in the background, so that you can get your scanning done and do the conversion overnight? (etc)
The documentation is also unbelievably bad: it's not task-oriented, there's factual mistakes where they copied and pasted out-of-date content from the prior model that doesn't apply to the S1500M, it buries the most critical things you need to know in tangents, and is written for an era in which users read a multi-hundred page document from back to back. If I were still teaching undergraduate technical communication, I would use it with my students for comic relief.
All that said, this scanner has enabled me to reclaim my closet and I'm very grateful for it. But it's far from a perfect product, and the flaws are ones that companies have no excuse for perpetuating at this price point, or in this era. Hopefully in 5 years there will be competitors that build fast scanners with reliable quality and well-crafted software -- but this ain't it.