It was a fairly old paperback, and I used their OCR.
it's possible that the higher DPI actully created more OCR problems than it solved, if spots on the page might have made their software mis-read a letter. I intend to do the next book with 300 DPI, and see if that's better or worse.
I'm converting duplicates of a rather obscure author of whom I am fond, slowly. I hope I can find some of her other fans to do the proofing for me, since I'm lousy at that.