mixed SSO authentication with SSL client cert and username/password

Hi!

I think to enable SSO authentication with SSL client certificates as described in docs ID 264868.1, 251167.1.

But SSL client certs will be used just for a couple lazy users , other users should be authenticated with manual username/password entering in SSO login page.

Am I quite right understanding that setting CertificateAuthFallback=true and SSLVerifyClient to "optional" will allow to achive this and 

- users that have no certificate installed will see no any warnings and errors and will be transparently redirected to SSO login page?

- users which have valid SSL client certificate installed will be automaticaly logged in.

Thanks!