In just about every language I seen people use .clone rather than deal with problems so I suspect a lot of cases a GC can be just fine or faster. Although I'm comfortable with memory management and rather use C or C++ if I'm writing fast code
Like in case where you can't use Rust? (ie.: existing codebase). Sure that is what Fil-C is good for. Point is that Fil-C does not solve the problem Rust does. It is more like band-aid. (Maybe my comment was misunderstood because of typo: sell/well)
Also I think there is huge difference between GC and fact that some people use .clone() somewhere.