result

Benchmark: running data_recursive, data_rmap, data_visitor for at least 1 CPU seconds...
data_recursive:  2 wallclock secs ( 1.01 usr +  0.00 sys =  1.01 CPU) @ 17970.30/s (n=18150)
 data_rmap:  1 wallclock secs ( 1.00 usr +  0.00 sys =  1.00 CPU) @ 7168.00/s (n=7168)
data_visitor:  1 wallclock secs ( 1.02 usr +  0.00 sys =  1.02 CPU) @ 6200.00/s (n=6324)
                  Rate   data_visitor      data_rmap data_recursive
data_visitor    6200/s             --           -14%           -65%
data_rmap       7168/s            16%             --           -60%
data_recursive 17970/s           190%           151%             --

script.pl

use warnings;
use utf8;
use Encode;
use Benchmark qw(:all);
use Data::Visitor::Encode;
use Data::Recursive::Encode;
use Data::Rmap ();

my $sample = sub { { key => ["これはサンプルです","これはサンプルです"] } };
use Devel::Peek;

my $cmp = timethese(
    -1,
    {
        data_recursive => sub {
            my $sample = $sample->();
            my ($s) = Data::Recursive::Encode->encode_utf8($sample);
        },
        data_visitor   => sub {
            my $sample = $sample->();
            Data::Visitor::Encode->encode('utf8', $sample);
        },
        data_rmap      => sub {
            my $sample = $sample->();
            Data::Rmap::rmap { $_ = Encode::encode_utf8($_) } $sample;
        },
    }
);

cmpthese $cmp;