Well, now you are comparing map/block with for/expression. Blocks are more expensive than expressions. And while this doesn't mean for isn't slightly faster than map, it does skew the results. Here's another benchmark, where we do a very simple thing in the block/expression:

#!/usr/bin/perl

use strict;
use warnings;

use Benchmark 'cmpthese';

cmpthese -2 => {
    map_block   =>  sub {my $s = 0; map {$s +=$_} 1 .. 1000;    $s},
    for_block   =>  sub {my $s = 0; for (1 .. 1000) {$s += $_}; $s},
    map_expr    =>  sub {my $s = 0; map $s += $_ => 1 .. 1000;  $s},
    for_expr    =>  sub {my $s = 0; $s += $_ for 1 .. 1000;     $s},
}
__END__
            Rate map_block  map_expr for_block  for_expr
map_block 3224/s        --       -4%      -10%      -17%
map_expr  3345/s        4%        --       -6%      -14%
for_block 3572/s       11%        7%        --       -8%
for_expr  3900/s       21%       17%        9%        --
[download]

map is slower than for, but the difference is in the same order as the difference between a for/expression and a for/block.

Abigail