The company that brought you the first out-of-the-box competitive Megaminx and revolutionary Dayan Guhong teamed up to make... a 4x4? And this cube only gets weirder from there.
Turning: Out of the box, the worst turning 4x4 on the market. Just atrocious. But, after tensioning, lubing, sanding off flash pieces, the cube becomes definitively more controllable and smooth, and speed starts to pick up. The corner cutting is about 1/3rd piece with no reverse, and needs tighter tensions because this cube POPS. Outer to Inner layer cuts will send edge pieces flying off the handle.
Design: The most revolutionary advancement to a ball core mechanism since its' very conception. The cube is designed with 4x4 cubies that wrap around a ball core, and the ball core itself is actually a 2x2 mechanism that allows the 4x4 centers to latch into the hooks of the outer corner shells of the core, and thus allow a function ball-core with screw spring capabilities: you can corner cut on the inner slices! Sadly, while this breakthrough was a cube engineer's masterpiece, the same basic issues of the ball core design are still present: popping edge pieces. The wings of the edge aren't wide enough for the center to keep them intact, so when too large a corner is tried to be cut, the cube becomes disastrous. Tighter tensions are HIGHLY recommended when using the cube.
Stickers: Standard dull, cheap stickers from the yester-year of cubing, with slightly brighter than expected green. Also, very few shops offer replacement stickers for the 66mm 4x4, so you'll have to look far and wide to get those replacements. Mine currently have cube smith half-brights, but hose work best for blocky 62mm 4x4's, and leave a fair bit of exposed plastic.
Final Verdict: This cube is essentially a project. If you're looking for a 4x4 that needs TLC, elbow grease, and a large amount of solves to make great, then step up to the plate. But cheaper, more manageable, and less labor intensive options do...