I have an Opticbook 3600, and my experience is similar to rkomar's. I have FineReader 11, which will export to epub, but I've found that FR11 still has problems sometimes with short lines with quotation marks, and problems with not recognizing paragraph continuation between pages, so you'll still need to postprocess it.
If you've got a couple of the right cameras, and you're willing to do some building yourself, there's
www.diybookscanner.org, which has several designs or examples of camera based scanners. I think you could probably do about 10 PPM with one of the 2 camera setups.