This plugin is doing a great job of blocking spam.
I used to use AVH First Defense + MP Spam Be Gone + Akismet and was still getting 6 - 10 spam/day.
I installed this plugin and have not received any spam since. I also removed AVH and MP Spam Be Gone and still don't receive any spam. I now only use this plugin and akismet, although I guess could probably even remove akismet now too...
Legitimate commenters seem to be able to leave comments without any problems.
So far, so good. Thanks for a great plugin.