Thank you for your quick reply and pointing me in the direction of Benchmark. Observant me didn't even think of time passed since the statement was made, but I figured since I asked the question I may as well go ahead and learn how to use Benchmark and get the answer. For anybody interested in the results:

For the sake of simplicity I used the code from the passage broken into subroutines to be called by Benchmark:

#!/usr/bin/perl 
use strict;
use warnings;

use Benchmark qw(:all);

my %h;

@h{'A'..'Z','a'..'z'} = 1..52;

sub verbose {
   my $hash = shift;
   foreach my $key (sort keys %$hash) {
      print "$key:   $hash->{$key}\n";
   }
}

sub idiom {
   my $hash = shift;
   print map "$_: $hash->{$_}\n", sort keys %$hash;
}

timethese(100000, {
   'Verbose' => 'verbose(\%h)',
   'Idiom' => 'idiom(\%h)',
});

timethese(1000000, {
   'Verbose' => 'verbose(\%h)',
   'Idiom' => 'idiom(\%h)',
});

timethese(10000000, {
   'Verbose' => 'verbose(\%h)',
   'Idiom' => 'idiom(\%h)',
});
[download]

RESULTS:

---

Benchmark: timing 100000 iterations of Idiom, Verbose...
Idiom: 0 wallclock secs ( 0.08 usr + 0.00 sys = 0.08 CPU) @ 1250000.00/s (n=100000)
(warning: too few iterations for a reliable count)
Verbose: 0 wallclock secs ( 0.12 usr + 0.00 sys = 0.12 CPU) @ 833333.33/s (n=100000)
(warning: too few iterations for a reliable count)

---

Benchmark: timing 1000000 iterations of Idiom, Verbose...
Idiom: 1 wallclock secs ( 0.76 usr + 0.00 sys = 0.76 CPU) @ 1315789.47/s (n=1000000)
Verbose: 1 wallclock secs ( 1.12 usr + 0.00 sys = 1.12 CPU) @ 892857.14/s (n=1000000)

---

Benchmark: timing 10000000 iterations of Idiom, Verbose...
Idiom: 8 wallclock secs ( 7.52 usr + 0.00 sys = 7.52 CPU) @ 1329787.23/s (n=10000000)
Verbose: 12 wallclock secs (11.76 usr + 0.00 sys = 11.76 CPU) @ 850340.14/s (n=10000000)

---

So at least for this particular piece of code map proves to be faster. Thanks again for helping me answer my own question. As always, I'm still a beginner so if this is misguided/messy code or i tested this wrong please let me know.