Did you actually test that code?

$ cat greengaroo.pl 
use strict;

my $ref = sub {
  print "Hello World!\n";
};

# Both are equivalent
$ref->();
&{ref}();
# But which one is best? That is the question!


$ perl greengaroo.pl 
Hello World!
Undefined subroutine &main::ref called at greengaroo.pl line 9.
[download]

your second call fails.

If you fix this by rewriting it thusly:

&{$ref}();
[download]

there is still the open question of "which is better?" From a readability standpoint I'd vote for the latter rather than the former. Others may disagree but that is the essence of TIMTOWTDI. If you feel there may be a performance issue involved here have you tried profiling the code?