OK, I see what they've done. For those who can't tell from the photos, this is essentially the YJ mechanism (modded V-cube) except:
- The core has a spring structure to help with inner-slice corner cutting.
- The hidden +centers don't have the tab, making inner slices smooth.
- The core contains two 'blocks', on faces adjacent to the center with two +centers attached, and the hidden +centers have little feet attachments inside the puzzle. When you do a double-layer turn this completely stops one layer from moving while leaving the other free.
So this should have outer layers as good as the YJ 4x4, but all three middle layers are clickless, and the mechanism cannot misalign. But it's still a variation on the V-cube design.