|Pic From Gamesworkshop|
In my personal opinion I not a fan of this unit. Despite it popularity i observe among player i have never gave this unit a chance. Its a nice looking model but i find it difficult to actually uses them. The reason why is
a) They don't do a whole lot in close combat and their survival rate is dependant to what the enemies are armed with.
b) They are expensive to be DOA into enemy lines to deal damage.
One big issue is lack on invul save. In the eyes of AP2/Ap1/power weapons they have the same survivability of an assault squad.
Their Glave Encarmine is power weapon regardless so odds wounding T:4 and above enemies are not alot. They can get powerfist but that add to already high point army and no alot of model or invul safe to keep Power Fist guy alive.
As mention of being expensive as DOA unit.their primary weapon is their Angelus Bolter which is nice taking out 4+ Sv unit but against MEQ and Elites it is another bolter. They can replace it by buying infernus or plasma pistol which can be effective but they are other unit that do more bang for their buck. From effective Assault Squad to Sternguard with Drop Pod or Honour Guard with Jump Pack
A special wargear they have is a death mask which must be purchase. It nice that any enemy in assault make Ld test and if fail cost them to be WS:1. It nice but odds are people arent gonna fail leadership that alot. Therefore feel like an expensive wargear.
Another option is to get Dante and make Sanguine Guard troops. Its nice being able to field 9 Sanguine Guard( 6 from troop and 3 from elites) squad but you aint gonna get alot of stuff with so much point going to Sanguine Guard and Dante.
Overall they are just too expensive to throw away for any drop and hard to justify their cost for a frontal assault unit.