Your skill will accomplish
what the force of many cannot
Using CGI to authenticate users is no less secure than using basic HTTP authentication, credentials are passed as plain text in both cases.
I don't claim to be an expert in anything. Thus I don't believe I would be able to do a CGI authentication routine better than the Apache programmers.
Summing up, my reply meant: are you sure you are able to do with a CGI a better job than apache does?
Many people could. I wouldn't. And I don't recommend to others what I wouldn't do myself.
About SSL and mod_perl, I preferred not to cite them. I preferred to focus on the intrinsic weaknesses of a self-made CGI authentication against an (already weak) basic authentication.
I subscribe your opinion on SSL and mod_perl, with a preference for SSL for the same reasons as before: personally I don't think I would be able to do with a self-made mod_perl handler a job better than SSL.