So far, it sure looks like a great plugin. Have you heard of any incompatibility with other plugins (except for Captchas)? I am quite fond of "paged comments" and I would rather keep it.
But I wish to modify the contact form, I get a field for phone (which I don't want). I commented out lines 322 and 323 in wp-spamfree.php and the field doesn't show on the form anymore. Now, I only have to find and comment out the related lines in the email form that is sent.