I had the plug numbers backward regarding standard plugs. I edited the post, but I wanted to let you know ASAP. Sorry..
I have an X12, but I admit I have not personally tried it. I can say two very good racers here that I pit with both have run it, so I have raced against it and feel very confident in recommending it. Like I said, I do have one based upon how it ran for friends that I trust.