I use several and it seems to be working although lately I keep getting the sorry page on google and can't figure out what is going on. It says that there are automated requests being performed by my computer when I try to search for something. I've run Avira, MS Security Essentials and Ad-Aware and can't find anything that is causing the problem.
I allow signature links on my sites but only after 10 posts. On one of my sites with wordpress I have Aksimet installed which throws obvious spam comments into an archived folder that I can later delete. If the user is providing useful content and contributing to the conversation, I don't mind allowing signatures. It encourages more people to come to my site which increases my traffic and my content.
Will there be filters kind of like Akismet for WP? It could be time consuming to have to individually approve every post.