> I can see some interest in Fil-C, but some will still be against it due to the overhead it imposes (1.5x-4x worse performance, less deterministic since there's a GC)

Yeah this is where I stand with it. Fil-C seems to be the worst of all worlds. It combines the performance of an immature GC language, with the primitive syntax and ecosystem of C. (Eg nullability, void*, no generics, no collection types, a bad standard library, header files, no good build system, bad cross-OS portability, BYO strings, etc).

I don't choose C for its wonderful syntax. I choose it because its small, light and performant. If I was happy to use a garbage collector, I'd much prefer to go all the way and grab Typescript, C# or Go.

The only use case I can see for Fil-C is running legacy code that you can't be bothered porting to a better language.