Your reviewer is severely misinformed about how perl works internally. Subs are compiled to an internal form just once, and at run time are accessed via the "CV" slot in a glob structure (f(...) form) or via the "SvRV" slot in a pad variable ($f->(...) form). There is almost no difference between the two.

I just tried profiling both forms on perl 5.22.0. Calling an empty function with 3 args used 665 x86_64 instruction reads for the direct form, and 675 for the indirect form: a 1.5% difference. For a real sub that actually does something in its body, the difference would be negligible.

Dave.