I built this project.
Building was a success. The blocks fit well and the techniques used are great fun. The variety of blocks also makes it very interesting. Although I had chosen a different solution on some points for more strength. There are a few points where the blocks fall off with a little tap (eg the rudder).
But: I am not really pleased with the instruction booklet. It is often unclear which blocks are meant. In addition, the biggest problem is the coloring of the booklet. The colors that are used do not resemble the colors of the block, so I got confused more often and I had to break off pieces because I had used the wrong color. If the three colors Gray, dark gray and black are in 1 construction point, it is visible, but if they are scattered, the confusion between these colors is very great.
What I do like is that the color of the already built piece is completely gray, which makes it easy to see what the new blocks are.
All in all, if the instruction booklet is adjusted, this is certainly a formidable competitor for Lego. Hope that they will soon do something with technical models (such as Lego has technical Lego)