Wouldn't look any different to me. 

If you go into your profile and click the Look and Layout Preferences, you'll see a list of adjustments you can make to the forum.  One of the options is Don't show users' signatures.  If you click that box, suddenly the forum signatures no longer exist.  It does make it a little more difficult to tell who is commenting on something because they have legitimate input vs those who are getting their quota in, but if the signatures are bothersome it's worth it.  Especially once you've built up a good ignore list.