Two things:
1) it works absurdly well - I zap someone, then everyone around just goes nuts on him/her, and I get rid of that person with zero consequences. This seems kind of overpowered.
2) it is however super fun!
I've been messing around trying to mezz everyone. Most epic was probably when I zapped Jericho, and he took out damn near the whole population of the town before I put him down. I've just downloaded a mezz-everyone mod, am going to try to enslave some annoying buttholes now.
Anyone have any Mesmetron stories, as well as suggestions on how to use it for maximum hilarity, or who to use it on? I'm thinking Sister in Rivet City, Lydia Montenegro, and 'President' Dave, so far.