The Data Seal of Approval (DSA) has been in use as a certification instrument for trustworthy digital repositories (TDRs) since 2010. By March 2016 some 50 repositories had applied successfully for the seal. Whereas some organizations and repositories have published about their own experiences in the certification process, no comprehensive overview was available of such practice-based evidence drawn from all DSA-certified repositories. Within the framework of a national project, a Dutch team fielded a survey to all DSA repositories. This report presents all collected (anonymized) responses and some basic analyses. Quantitative and qualitative evidence submitted in the survey is presented in Annex 2, and summarized in this report. The data strongly indicates that while the respondents report considerable (though varying) levels of investment of staff resources in the certification process, they also recognize and emphasize the benefits of the exercise and clearly recommend this type of certification to their peers.