I use ETL::Yertl a lot. Despite its present unpolished state, it contains some important, easy-to-use tools that I need to get my work done. For example, this week I got an e-mail from Slaven (a CPAN tester and a tireless reporter of CPAN issues found by testing) saying that some records were missing from one the APIs on CPAN Testers: The fast-matrix had 3300 records for the "forks" distribution version 0.36, but the matrix had only 300 records. The utilities in ETL::Yertl made it easy to find and manipulate the data I needed to diagnose this problem.