You can have convenience, or you can have fast. Pick one. Convenience in this context == threads, which means you're not compressing program state very much,

You can have convenience, or you can have fast. Pick one. Convenience in this context == threads, which means you're not compressing program state very much, which means your program will have a larger memory and cache footprint. Fast in this context == compressing state by expressing it explicitly rather than implicitly in the call stack. You can compress the most by writing directly in CPS style. You can get the most convenience by using threads. Everything else is somewhere in the middle. Now, choose your poison.