I have to agree again. There are some really cool packages but I hesitate since many years to use them. That includes all the RegEx modules -- I have never used regex in Nim, while I used it from the beginning in Ruby (Regex is part of the Ruby language.). Same for Yaml vs Json, I heard people say NimYaml is a cool package, but I never dare to use it. Or criterion, was nice, but author retired, so I never used it again. Sad. (And yes, I know there is a fork, but I never use forks, smells like theft for me.)
But I think I should really dare to use more external packages. At least I use the combinatorics.nim code provided by Mr. R. Behrends for many years for gintro now, but unfortunately that code never made it into a nimble package.