If a benchmark shows a difference of less than 50%, you might as well consider them the same, except for the perl and the environment you ran the test on. And then just for the test data. Compiling it with a different compiler, or different compiler settings may show a reverse result.
I'm pretty sure Damian doesn't favour map over for because of performance.
Don't take PBP as a gospel. That would be against the spirit of PBP. Take PBP as a starting point to make up your own mind.
If you prefer for over map, by all means, use for. Doing things *your* way, that's the Perl spirit.
Snippets of code should be wrapped in
<code> tags not<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).