I have some of the ASD Proto, along with a large selection of the older ones. Both work, I didn't notice a real deficiency in the older ones, and the newer ones work just as well. I rarely have to use an open end at full torque, so I suspect that's the reason I don't see a difference; I don't doubt the ADD work better on tough nuts. I also have some of the Snap-on, and again, not a lot of difference between them and the Proto, or between the older ones I have and the flank drive. I prefer the Proto, but that's a personal preference, not that I feel that they're better.
At this quality level, the differences in wrenches are subtle. They are significant in certain extreme situations, and that's exactly why the design was developed.