keith may also be right, but my copy of the rules came from the Annual 2002, which I found on eBay.
I would say vs chaos and VC (TK to some extent) go for it, many VC characters cost more than 350pts and there you have 2 characters that can basically 3 S8 and 2 S6 hits, combined with the prayers (hammer of sigmar and armour of contempt come to mind) and the potential to kill vampires outright (which won't be too difficult with S8, even 1+ armour becomes 6+ and you wound on a 2+) if you charge them cast HoS, if you get charged cast AoC.
Even against normal undead and daemons the auto wound staff and S8 stake will butcher tough units like grave guard and blacks knights, as well as daemons. The only immediate downside is total lack of any save unless you cast AoC.