Who are they targeted to? For example, .gov sites in the USA are required to comply with Section 508 accessibility design for their sites and this is why they offer resources in several alternative formats like .pdf. Search engines aren't the only end "user" who needs text to understand content. Consider, too, that some colleges and universities purposely code for at least WCAG2.0 accessibility compliance for their public facing pages because they serve special needs people. I would offer both versions and label each choice with the format, pages, and size if you know it.