What uses have you found for obliterators. In my experience, they are a terrible large army unit but the best "Oh crap" unit in the game. Their extremely low cost makes them the strongest unit per requisition point, but their high population cost means that they just don't have enough power.
I have won numerous games because of obliterators (including one team game where I was reduced to my HQ (a rebuilt one), my Daemon pit (my ally saved it), my relic, and a couple power generators. Obliterators allowed me to still make a major contribution to my ally, especially since deep strike and personal teleporters let me send them straight to the battlefield.
On the other hand, their power to population ratio is bad enough that if you aren't badly struggling for requisition, they are just too weak to be worth using.
Agree, Disagree? I am hoping to find more uses for obliterators (as they're one of the coolest units in the game).