Great puzzle but really difficult! Definitely provides more of a challenge than a regular 4x4 cube, you need to think a lot more about the rotation of each piece.
The turning is actually pretty smooth, but there's no magnets and the shape is quite awkward at times, so it's quite easy to mess up algorithms if you're not careful. If there's an equivalent cube that has magnets I think that might be a lot better, but personally I'm happy with this for now.
(also i think the colours are nice)