To me this puzzle is a miracle, for a 9x9 to be this small and fully functional is simply not possible in my mind, it is literally small enough to hold comfortably and fingertrick. I also have a Shengshou 10x10 and it is giant, it feels big, and that's the point of a big nxnxn cube ... to feel big. But this 9x9 flips that and is impressive for how small it is. This is truly a demonstration of how far cubing tech has come.
In terms of quality, the colour scheme is great (mine is stickerless) and it feels like a decently well built puzzle with good materials and textures, but the obvious side effect of stuffing 9 layers into such a small space is some sacrifices in turning quality. Once you get a turn started it is pretty smooth, however you do need to be a bit careful with the alignment of the layers before turning. I use this puzzle gently and there's a lot of times where you feel like you're close to a pop. So this puzzle is a compromise in a way, BUT at the moment of writing this review I have only had the puzzle for a few days and haven't used it a huge amount, it may improve drastically when it has been broken in, and I have seen plenty of reviews praise the turning itself.
If you want the best 9x9 period, don't get this. You'll prefer something larger like a Yuxin 9x9 which turns better. But if you want a "small big cube", something which simply hasn't existed until this point in time, something which pushes the boundaries of cubing tech, this is for you. I personally love it to bits.