Comment by vacuity
Along with the sibling comment, microbenchmarks should not be used as authoritative data when the use case is full applications. For that matter, highly optimized Java or Go may be "1 to 4 times as slow as plain C". Fil-C has its merits, but they should be described carefully, just with any technology.
I replied to unwarranted (to my eye) call that Fil-C is significantly slower than plain C.
Fil-C has its drawbacks, but they should be described carefully, just with any technology.