The global COVID-19 pandemic has had a considerable impact on the scientific enterprise, including scholarly publication and peer-review practices. Several studies have assessed these impacts, showing among others that medical journals have strongly accelerated their review processes for COVID-19-related content. This has raised questions and concerns regarding the quality of the review process and the standards to which manuscripts are held for publication. To address these questions, this study sets out to assess qualitative differences in review reports and editorial decision letters for COVID-19 related, articles not related to COVID-19 published during the 2020 pandemic, and articles published before the pandemic. It employs the open peer-review model at the "British Medical Journal" and "eLife" to study the content of review reports, editorial decisions, author responses, and open reader comments. It finds no clear differences between the review processes of articles not related to COVID-19 published during or before the pandemic. However, it does find notable diversity between COVID-19 and non-COVID-19-related articles, including fewer requests for additional experiments, more cooperative comments, and different suggestions to address too strong claims. In general, the findings suggest that both reviewers and journal editors implicitly and explicitly use different quality criteria to assess COVID-19-related manuscripts, hence transforming science's main evaluation mechanism for their underlying studies and potentially affecting their public dissemination.