I'm active on a site that uses WPSpamFree, and it's like pulling teeth to get a comment accepted. Virtually everything I try to post gets blocked as spam. This is even if it includes no links or URLs or anything else remotely spammy. At one point, I had to break a longish comment into four separate comments to get it through... but later on, even a less lengthy comment that was shorter than one of the pieces of the previous comment still got blocked. Apparently there's just something about my writing style that SpamFree doesn't like, but since it gives no feedback as to why my comments are blocked as spam, I don't even know what I can do differently to get my comments through. It's immensely frustrating, and I've asked the administrator of the site to consider using a different spam protection method.