is there a better (?define!) alternative to Apache for PC-based (ie non-server based) CGI testing of perl scripts?

The alternative I would suggest is not to use a webserver at all. CGI scripts can be perfectly adequately tested without a webserver by setting the environment correctly and optionally providing the input data on STDIN. eg.

use strict;
use warnings;

use Test::More tests => 2;

$ENV{REQUEST_METHOD}  = 'GET';
$ENV{QUERY_STRING}    = 'game=chess&game=ludo&weather=dull';
$ENV{PATH_INFO}       = '/somewhere/else';
$ENV{PATH_TRANSLATED} = '/usr/local/somewhere/else';
$ENV{SCRIPT_NAME}     = '/cgi-bin/foo.cgi';
$ENV{SERVER_PROTOCOL} = 'HTTP/1.0';
$ENV{SERVER_PORT}     = 80;
$ENV{SERVER_NAME}     = 'here.there.com';

my $out = `/path/to/my/script.cgi`;

like ($out, qr/Content-type: text\/html/, 'HTML response');
like ($out, qr/foo/, 'Foo found');
[download]

Depending on the actual deliverable, this may well be all you need.