Is there ever a scenario when it's preferrable to use the &

There is one dramatic difference that occurs when you call the function without a parameter list:

#! /usr/local/bin/perl -w

use strict;

sub inner {
    print "  inner: $_\n" for @_;
}

sub outer {
    print "outer: $_\n" for @_;
        inner;
        print "\n";
}

sub outer_amp {
    print "outer_amp: $_\n" for @_;
        &inner;
        print "\n";
}

outer( qw/ vroon gukguk faba / );

outer_amp( qw/ foomp tweedle zachitty / );

__RESULTS__

outer: vroon
outer: gukguk
outer: faba

outer_amp: foomp
outer_amp: tweedle
outer_amp: zachitty
  inner: foomp
  inner: tweedle
  inner: zachitty
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When using the &inner variant, whatever remains of @_ in the calling routine is passed to the called routine. The only time it's really useful is when doing out-of-the-ordinary stuff like autoloading. In general you should avoid it. It leads to bad surprises

PS: metasyntactic function call arguments courtesy of BooK's Acme::MetaSyntactic module, the donmartin theme.