I played a 2,000 point game today and my opponent and I agreed to try out our Lords of War. I've owned a cobra for years, but had yet to deploy it in 8th. He had recently finished a knight, so we gave it a shot.
He fielded a mostly mechanized IG list with 3 leman russ tanks, a basilisk, colossus bombard, knight commander pask, and (of course) his knight. He also had about 50 guardsmen and a couple of assorted characters (none of which made a big impact. We played "Big Guns Never Tire," which seemed appropriate since we were both deploying our largest models.
I ended up with 3 of the 4 objectives in my deployment zone on a search and destroy setup, so I positioned on the objectives with a large dire avenger screen, with rangers, war walkers, reapers, farseer, reaper autarch and such behind the screen, leaving room to bring the tank in on my first movement phase. This way, he had to come to me (tough break for him).
He sends his column of vehicles at me 5" at a time to take advantage of grinding advance, kills all the war walkers on turn 1 and a couple reapers and rangers. I drop the cobra in response and one-shot his knight while the reapers blew up a doomed and jinxed Pask who had foolishly charged straight in on his first movement phase. We were both kind of stunned, but what followed was a tank-busting party of epic proportions. The cobra killed a tank every turn until they were all dead, and the reapers busted a couple as well. The 40 dire avengers had no problem out-shooting 50 guardsmen, and it was a wipe by the end of turn 4. After his first round of fire he pretty much fired everything that wasn't a lasgun at the cobra, but between fortune, fieldcraft, and lightning fast reactions he couldn't damage it effectively. It finished the battle with 14 / 26 wounds.
At one point the cobra put 37 wounds on a leman russ in one volley (this was the highest either of us had seen). I can only imagine the level crazy something like that would have if I buy a bonesinger model and start using it to repair the tank from behind.
Thus comes the question - has anyone fielded or fought cobras in 8th and have you found them to be as devastating as I did today? It almost didn't seem fair that his knight cost almost as many points as the cobra, but went down with such ease. Is this an overpowered "cheese" unit in your opinion, or did my opponents list just happen to be the kind of thing that played to the cobra's strengths?