At the OKC show IM had the two rough(very rough!) prototyped mechanisms. It seemed to me there were some differences in them, but I held the "more compleated" one in my hand a minute or two(being EXTREMLY careful with it...that could have represented $50,000 easily!). The IM people were being very firm that they would get them "right", rather than "sooner". They were planning them to be "DCC plug-in ready" in Dec. That could change easily. IM was making provisions for sound to be added in the tender, which they didn't have one of to show.(Grille in the bottom of the tender... oooh, so hard!) With the "issues" in the Chinese plants, I wouldn't be surprised if the AC-12's don't hit the shelves about Labor Day, or even later. If the mechanism they were showing in Dec wasn't good, they may have gone back to the CAD/CAM screens. I'd rather have it good than fast, myself.