Just received some more scans. The scan quality for this new batch is very, very good. The quality was similar to or even better than the scans I do myself. I'm thinking the discrepancy from the first set may be due to a change in paper quality. The publishing company used better quality paper for the reprints and later volumes. I'm very, very happy with the service.
Only sent graphic novels for now, though, so no experience with actual books and OCR. I've still got hundreds of books. Will likely make good use of the Platinum Membership for a year or so.