I took a peek at 'Death From the Skies' 40K Supplement, specifically, at the Fighter Ace upgrade for qualified armies. First, the Fighter Ace upgrade may be purchased by any unit with the 'flyer' special rule for 50 points. An is then chosen at random from an army-specific list.
A player rolls a D6 per Fighter Ace upgrade purchased to randomly generate one of three special abilities on their Army's Fighter Ace specific table. I noticed that the IG and SM Fighter Ace tables provide a chance for a +1 AV upgrade to the model's front AV rating. In essence, a Vendetta could have front armor AV13, and a Storm Raven AV13.
Blood Angels may roll an option that allows the model to pivot up to 180 degrees each turn (rather than 90), and, an option to give all units within 12 inches of the model get to reroll all failed to hits in shooting and assault.
The Fighter Ace table looks fun, but, sacrificing 50 points to unlock the dice roll for a 33% chance at a beneficial special rule doesn't seem very competitive.