Has anyone tried using SI Captcha Anti-Spam with Defensio Anti-Spam instead of Akismet? I would expect that if this Captcha plugin works with Akismet that it should work fine with Defensio as I think Defensio works similarly to Akismet. I'm trying out Defensio on a new blog in part because their pricing structure is a better fit for me (I've also read some decent reviews about them).
I'm going to try out Defensio and SI Captcha together and see what happens, but I'd appreciate hearing from anyone who has also used these two together, especially if there were an incompatibility issues. I'll also post back regarding my experience.