I've used it three times, just to see the different effects of it. I don't find it to be incredibly useful and tend to stick with !Condemn, because I have never had Doom fail me on any guy I have used it on. The other ones are pretty useless by the time you get the Oracle.

About the only new class that I have found any use with is the Gladiator, and that's only marginal. Cannoneer is alright, but not too great. I've yet to get the Necromancer.