"It also supports automatic style composition for multiple composed Fela components." would be really nice, and allows passing props, so essentially handles most of the logic done constelation components.
fela might help, but only a little. All css-in-js libs sacrifice a bit of performance for convenience. I'm waiting for the one that'll compile away via a babel transform.
Could be more performant. Has support for themeing and react native.
http://fela.js.org/docs/guides/UsageWithReact.html
https://medium.com/@rofrischmann/styles-as-functions-of-state-1885627a63f7#.9s9uglt7e https://github.com/rofrischmann/fela/blob/master/packages/react-fela/docs/createComponent.md