Since there aren't even any whispers, of hints, of shadows of rumors about a new Witch Hunters book I think I've got time.
I want to use them as both a distraction (Facing psychers? Keep them close to the blob and
CCS to negate any area effect psy powers.) and as basic ass kickers. I figure that with two templates and 14 shots I could generate a lot of hits with a decent chance of AP1. And in
HtH having a unit in Power Armor with I4 and, effectively, anti-personnel Rending that always hits on a 3+ is a really good thing. And if they charge while ≤12" from Straken it's even better.
@svendrex - Converting them to uber-
CC is just too damned expensive and not all that interesting to me. But to cover your 3 comparative points:
1) The Vets with 3 Meltas would be somewhat cheaper. And have more shots per turn of Melta. But they wouldn't have Bolters, or flame templates, or
PA, or I4, or Acts of Faith, or Shield of Faith, or...
2) I've got Heavy Flamers on both Chimera and one of the Russ. But none of them can turn into S5/AP1.
3) But the Commissar is an
IC and while his bubble is nice, he tends to shoot failures and isn't all that impressive in either shooting or
CC. He's also more expensive with no gear than my Canoness with all her equipment.