I got this set really long ago, and although I was very excited to try it, and I thought it was a very nice idea, I just recently tried it out.
The colors are very vivid, and beautiful and the pens are very easy to use, no effort and they paint, which means you do not damage the polish under. The Black base chalk coat, looks really good and it is a black matte. It is very tricky to apply because it dries out immediately. Even if you have not finish the nail, the best strategy is to wait for that to dry and then apply on the rest a fresh coat. Otherwise you just start peeling, the semi dry layers. Do not worry about that because the finish is such that you wont notice it much once all the layers are dry, and the pop of colors also distracts from the fact the first layer is not perfect. The matte top coat is really nice and it stays matte unlike others.
The bad news about these is that it lasts one or two days and it starts chipping off. In my opinion is too much work for too little time. I do not think you need this particular set, the only product I would keep using is the matte top coat. The best one I have tried so far, when it comes to the effect.
Have you tried these? Did you like them?