I'm not being ignorant at all. I've been frustrating myself with ballmech 4x4s for 4 years now, and I can say, there is not a huge list of positives. I think it is perhaps the best mechanism for a 4x4 for its qualities as a 4x4, but every downside makes it horrific for a 3x3 mechanism. Unless you can tell me otherwise, I firmly believe that the negatives associated with a 4x4 ball mechanism will carry over to this design.
Oops, I was gonna include an explaination for how the ball mech in this particular case would work, but forgot to. Silly me
I was gonna say that this core is a bit different from the 4x4 ball mech (which you didn't realize). Basically, the cube have springs inside the core to enhance corner-cutting. The main reasons why the ball mech 4x4 is horrible is because 1) there are no springs to allow some flexible space to glide over misallignments, and 2) the center pieces slides inside the groove rather than freely moving over each other.
The first reason makes the outr layer unforgiving, and the second causes the biitching inner layers.
Now in this case of the DaYan, neither of those designs are present. If you see a "big picture" the cube is pretty much a normal Dayan (the original) 3x3 with a fancy core. The core is very likely to be double-layered, so basically screws could be pulled outward with the spring pushing it back.
The advantage of this core is that the ball shape helps pushing the pieces back during corner-cutting. What I mean is that when you take a corner at a large angle in a normal 3x3, if the spring does not have a lot of force, the structure feels floppy and deformable, which causes lockups with pieces catching on each other. But with the ball core the surface provides a basic support for the allignment of the pieces, so it have the advantage of a spring structure but with more solidness.
But really, these are just empty talks and not practical. It's the real thing that matters.
EDIT: excuse my grammar in this one, I wrote this in a hurry.
