I ran a couple mock battles with them and found them to be not as bad as I initially thought. Having a 5++ save, FNP, and T3 is far from ideal; however, being Zealot ensures they won't flee. In close combat the Fulgurites did relatively well against Orks and even DE Grotesques, but only when paired with an appropriate canticle. I still think they aren't good on paper due to their cost; however, they may not be as bad as i initially thought. The Corpuscarii is another story since their 12" range IS terrible.