The Qiyi Qimeng plus is a 9cm 3x3, but the regular size is 5.6cm. It's really weird and interesting to use, I can kind of do finger-tricks on it like a normal cube, but they are a little harder. Regardless, it is still an awesome cube to use.
OOTB the cube is a bit tight, but loosening it did help. Then it could corner-cut 45 degrees, which is surprising considering the size. And it can reverse corner-cut about two-thirds of a cubie. It does come with a bit of lube inside as well.
The turning experience is great. Smooth when turning slowly, but crunchy when turning fast. There is a bit of spring noise, but I don't mind this. It is a bit loud though. The really hilarious part is when you use this cube for quite a bit, then switch back to a normal cube, and it feels tiny.
The plastic is frosted on the outside, but I've had this for about 2 weeks and it looks shiny. The shades are the exact same as the Qiyi MS cubes, probably my favourite colour scheme.
For being only 12$, this cube is a "must-get" for puzzle collectors or even Speedcubers. It gives the visually appealing size difference, while still being able to turn well. Overall, If you want to get this cube and you are unsure whether to get it or not, you won't regret it.