Actually you completely fail to understand how CGI.pm works. When you use CGI; you import 0 methods. The methods are available via the OO interface and compiled on demand. When you use CGI qw/:cgi/; you import and compile the basic cgi methods (which you would otherwise not do with a straight use CGI;). As we are making OO calls this is a complete waste of time. Running your example you can see that the time remains essentially the same as expected (loading the extra methods once (with the use CGI qw/:cgi/;) adds about a second to the load time but this is a once off price and we are then looping.

use Benchmark;
use CGI qw/:cgi /;
use CGI::Simple;
$ENV{'QUERY_STRING'} = 'foo=bar&baz=boo';
$q = new CGI;
$s = new CGI::Simple;
timethese(250000, {'CGI' =>'$q->param("baz")', 'Simple' => '$s->param(
+"baz")'});

__DATA__
Benchmark: timing 250000 iterations of CGI, Simple...
       CGI: 29 wallclock secs (27.53 usr +  0.00 sys = 27.53 CPU) @ 90
+81.00/s (n=250000)
       Simple: 10 wallclock secs ( 9.99 usr +  0.00 sys =  9.99 CPU) @
+ 25025.03/s (n=250000)
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print