For those who use Chicken Scheme: what made you pick it over other Lisps? What are some things it does particularly well?
The compiler. That’s the gem of the system.
The generated C is reasonably portable, so you can run Scheme programs on systems that “don’t run Scheme”.
Self-contained, compact, compiled, fast, ready to use.
SBCL is not compact and its "image" concept is not universally liked by everyone.
Guile and Racket are not fast (nor compact).
Chez Scheme is not "ready to use".
The eggs are great. For instance I can be up and running building an SDL2 game or make a webserver quickly.
It has good emacs support with geiser-chicken.
Because it compiles down to C the FFI provides a lot of nice ergonomics beyond what I get with Chez Scheme.
Error messages are actually useful with a stacktrace. Can't overstate this.
It supports optional type definitions which reduces the number of tests I need.
The docs are adequate, though I frequently add "MIT scheme" to my search queries. I wasn't able to get chicken-doc setup in NixOS, and the docs website has gone down on me a bunch lately. I wish Chicken had complete documentation available including its eggs in an offline format, like a PDF.