@godless
I never said that 18 dead marines was a good thing, well less you are on the other side of the battle field

but with the amount of firepower being sent down range 18 not so bad. If it were orcs taking the same salvo they would lose round 36 boyz a turn.
you are right that you have to factor in the other firepower in the army. but you give to much credit to the ravengers but yeah between 1 and 2 marines a turn each but thats not what they were meant for so will not make up their points.
Also if the guys inside the venom want to fire effectively venom cannot move (depending on weapons) and if it moves more then 6 no troops inside can shoot. If it moves guys inside count as moving bye heavy weaps. and if the venom gets close enough for them all to bring weapons to bear you will be in range of them as well.
Svendrex above armylist is the bane of venom spam no doubt it is one of the best ways to go. I was just saying that there is not just one way to skin a dark eldar. No reason to be afraid of trying something different worse that will happen is you lose.