Here’s why I like the junk filtering in Movable Type 3.2. The screenshot is from an item of trackback spam, and though most of my comment and trackback spam doesn’t trigger so many rules, when configured, MT will not rely on one sole rule for marking something as junk. It also actually tells the blog administrator why a comment was marked as spam, or otherwise.
In other words, say Akismet said that this was ‘ham’, i.e. not spam – SpamLookup’s rules would work against it, and as the overall average feedback score would be less than 0 it would be marked as junk (comments which Akismet thinks are not spam get +1 instead of -1). And vice-versa.