If you've got some specific issues you've come across that lead you to think you can't use it it might help to enumerate on those

I'd missed that Template could output to somewhere other than STDOUT! Having gone back and looked at the documentation, I see what I had missed!

Is something like this the right way to do it (untested):

my $mail;
$template->process('mail.tt', $vars, \$mail) || die "Template problem!
+";

my $mime = MIME::Lite->new(
    From     => 'abc@xyz.com',
    To       => 'you@yours.com',
    Subject  => 'Test',
    Type     => 'text/html',
    Date     =>  $mail,
);
$mime->send;
[download]

Or does it need something more than that - other than error checking and validation of course.