CSS clean-up @ build time

Here is a simple Maven goal to optimize CSS delivery at build time and low cost.

<!-- set path to CSS files -->
<set var="css.cleanup.src.dir" value="path_to_css_files" />

<goal name="cleanup-css" description="Remove comments and blank lines from CSS files">
  <echo message="Removing comments and blank lines from files in ${css.cleanup.src.dir}" />
  <!--
    remove single+multiline comments,
    see docs@http://ant.apache.org/manual/OptionalTasks/replaceregexp.html
  -->
  <replaceregexp byline="false" flags="gm">
    <regexp pattern="\/\*(.\s)*?\*\/" />
    <substitution expression="" />
    <fileset dir="${css.cleanup.src.dir}">
      <include name="*.css" />
    </fileset>
  </replaceregexp>

  <!-- remove multiple blank lines -->
  <replaceregexp byline="false" flags="gm">
    <regexp pattern="^\r\n^\n" />
    <substitution expression="" />
    <fileset dir="${css.cleanup.src.dir}">
      <include name="*.css" />
    </fileset>
  </replaceregexp>
</goal>

Is it really worth it?
I tested it on 5 CSS files (test1.css, test2.css,test3.css, test4.css, test5.css) of different sizes and obtained a respectable file size reduction. In addition, dev comments are not shipped and exposed to the outside world.

Below is the output of the Python stats scripts I wrote to analyse situations like this (testX_c.css is the compressed version of the original file):

>>> describe(cmpfilesizelist(d, listfiles(d, "*.css")))

file test1.css is 4.57% larger than test1_c.css
file test2.css is 33.40% larger than test2_c.css
file test3.css is 21.93% larger than test3_c.css
file test4.css is 34.55% larger than test4_c.css
file test5.css is 36.54% larger than test5_c.css

('Sample Size: 5', 'Min/Max: ', (4.5725935634192512, 36.543124350536885), 'Mean: 26.20', 'Median: 33.40', 'Std. Dev: 13.37', 'Std. Error: 5.98')

The compressed files also validated on the w3c CSS validator