Author here. I agree, Timbre is new, and has some rough edges, but in my projects, I've found them worth putting up with. In my current project (18k LoClojure), I think the only serious dependency I have that uses j.u.logging or SLF4J is Datomic. Timbre has an interop library that will pipe java logs through timbre.

I agree knowledge of how Java logging works is still useful, but I'm not willing to be part of the problem anymore :-)

Agreed on Schema, and how it illustrates deficiencies in the type system. I still want core.typed, or something like it, but it's too immature for production use.