Performance with Perl Strings

I've been running across a lot of Perl code that breaks long strings up this way:

my $string = "Hi, I am a very long and chatty string that just won't";
$string .= " quit.  I'm going to keep going, and going, and going,";
$string .= " kind of like the Energizer bunny.  What are you going to";
$string .= " do about it?";

From my background with Java, building a string like this would be a performance no-no. Is the same true with Perl? In my searches, I have read that using join on an array of strings is the fastest way to concatenate strings, but what about when you just want to break up a string for readability? Is it better to write:

my $string = "Hi, I am a very long and chatty string that just won't" .
    " quit.  I'm going to keep going, and going, and going," .
    " kind of like the Energizer bunny.  What are you going to" .
    " do about it?";

Or do I use join, or how should it be done?