I think it really depends on the context and tools. I've come to believe, for instance, that trying to do logging configuration any way other than just using a

I think it really depends on the context and tools. I've come to believe, for instance, that trying to do logging configuration any way other than just using a standard log4j.properties file is a path to madness; at the same time, Lein profiles are a potent and idiomatic way to do certain types of environment configuration. The biggest argument in favor of more friendly config files for me is that they're easier to toss in a jar, though. Nobody wants to fight against configuration in their production environment.