I want to believe in Incubi but the main problem I have had is that T3 thing, which again, is kind of an army wide problem that could have been addressed in this dex.
Their transport is a prime target. It will get shot down, it is just a matter of how close you can get them to the enemy. Then I'll typically lose one in an explosion, maybe then get pinned and watch as they are bathed in a lovely wave of shooting with 2s or 3s to wound. 3+ armour won't hold. Then I find I regret taking a knife to a gunfight.
What Incubi and other open topped transport units need is a characteristic test against explosions. Initiative tests followed by a Dangerous Terrain check would circumvent the loss of squad members. OT gets really harshly treated in the rules.
Assault grenades. Duh. Where have they all gone!? I do want to run Drazhar and co, they look so good, but it just hasn't worked.
Kia Kaha, Dark Eldar players!