This video got me to thinking about this. Which move do you prefer, the RKO or the Diamond Cutter?
Me, I think the application of the Diamond Cutter looks better. I like how DDP used both hands to apply the move. He touches on the how and whys of that in this video even. Also, WWE does a good job of selling that Orton can hit the RKO at anytime, out of anywhere. They've had some cool spots with it as well, but I think DDP's application of that same idea was much better. It was a really versatile move the way DDP used it. He often hit it on some really cool reversals as well.
All-in-all, I think the Diamond Cutter was a better move. I would be interested to know if anyone prefers the RKO though.