I purchased the Diablo Edge Irons about a month ago from Golfsmith. I tried both the Diablo Edge and X-22 irons (among others) with the launch monitor and the pro who was helping me said, with the Diablo's I was putting less sidespin on the ball and hitting the ball about 5-10 yards further. I'm guessing the deeper cavity back makes them more forgiving, if you occasionally hook or slice the ball, and adds a little distance.
I've had them for about a month and have gone from shooting around 100 to low 90s/high 80s. I attribute some of that improvement to the clubs and some to improving my overall game.