I wiped/reloaded my iPad 3 for a second time, deleted any trace of the problem book, requested another download from iTunes Support, and installed a new copy of the book. No change. I further tested the same book on my iPhone 5. Still no change, while all other books remained snappy to page turning and other functions on all devices. The obvious conclusion was that there was an issue with the way the book was formatted and/or digitslly constructed. iTunes Support gave me a complete refund for the book without any hassle.
So, I guess that sometimes there is a problem with the media and not the machine. If you are having a similar problem with a book, you should try all the troubleshooting that you can to iscolate the issue, but take comfort in knowing that a refund can be had if the problem persists.