Not exactly the most comprehensive review here, but Jerome is really good. You get:

• +1
• The equivalent of Ward of Protection or Forewarned for the low low cost of 2 icons (you can even be a team player with this)
• 4 horror soak (well 3, because you probably don't want him to die, but that's still quite a lot)

On top of that, he only costs 2 resources to install (two resources and a actually, but few allies can be played as a ).

That all being said, he's probably best for a cluever (because that's who wants that passive boost), and especially for the faction, because they tend to have the most icons.