BILLD  I've been using a ScanSnap for 4 years now, and it has been a delight. I've run thousands of pages through it, most of them for OCR in DEVONthink Pro Office. I have never had a hardware failure, so I've got to say the ScanSnap is rugged and holds up well. Image quality has been very satisfactory for OCR.

Scanning speed is very good, even with my first-generation Mac version of the ScanSnap. Much of my copy is two-sided and duplex scanning effectively doubles output speed. The software ignores blank pages if the copy is single-sided, so no user action is required.

From time to time I've used most of the options in ScanSnap Manager Settings. I find them useful and easy to adapt to the copy I'm working with.

For example, paper that has been previously stapled or folded may tend to misfeed in the document feeder. Theres a Settings option to allow page at a time loading mixed with stack feeding, which compiles the output to a single PDF when the 'Finish' button on the computer screen display is clicked. This also allows one to intersperse pages of differing sizes into the same PDF.

I'm puzzled by the negative comments by another user about the ScanSnap's ability to adapt to various sizes of paper copy. I routinely scan a variety of paper documents with different sizes, and everything works simply and reliably. Just adjust the sliding plastic width indicators in the feeder and insert the copy in portrait mode. Checks, business cards, postcards, whatever, up to the maximum width of the document feeder. Comment: I've owned a PaperPort scanner in the past, and I think the ScanSnap is head and shoulders better both in hardware and software execution.

I've also got a flatbed scanner to handle scanning of bound copy such as books and journals. I regard it as a necessity, but I hate to do scanning in that mode, as it is so much slower and feels like drudgery, compared to the ScanSnap.  
(Version 3.0.20)

MARUKO DRINKING TEAM  This is one of the best Mac scanner drivers I've ever seen. No Carbon/legacy junk, generally just keeps working across major system updates. There are a few quirks, like not using Mac standard keyboard shortcuts within the app (Cmd-S to open Preferences? Really??) but it generally works reliably, and can be configured to hand off a PDF of your just-scanned document to the app of your choice.   
(Version 2.2L11)

CENOCRE  It works consistently and is stable and is fine if all you do is scan one or two normal paper sizes. Otherwise, this software is unacceptable in its flaws and has an unnecessarily complex interface. They could do everything in one clean panel rather than having around a half dozen. It seems like the software developers have not studied how people actually use the scanner and software.

When using various paper sizes, especially automatic paper sizes, it is awful. It won't even scan a normal business size check correctly. Visioneer Paperport had MUCH better size detection nearly 20 years ago!!!!!! Why can't Fujitsu keep up with old technology? Bizarrely, auto does not really match your paper size. It just goes to the nearest preset size and rather than match the size or go bigger, it will often go to a smaller size and crop off part of your document causing you to lose data. This is completely stupid on the part of the software developers. Extra white space is better than losing data.

If Paperport were still Mac compatible I would use it in a heartbeat as the interface and features are far easier and superior. Unfortunately, the Fujitsu is the best scanner for the Mac and this lousy software is what comes with it.  
(Version 2.2L11)