Well I've seen other reviews saying they're not as good but I ordered them anyway. I figured if they weren't that good I might ONLY use this kit on aluminum. I haven't used this set yet, but I have some feedback and tips. The smaller ones looked chipped at first, but it wasn't until I looked at the largest windmill that I realized why the smaller ones were chipped. Each cutting surface has a sharpening burr. They sharpen these bits and then just ship them without deburring the back of each blade. So now I'm warning you, prepare to debur every cut surface on any of these tools. I bought a used set at about 20% off and they seem good, last user had 2 or 3 full trees. Doesn't look bad, I haven't used them but I'm thrilled too and I definitely feel like they should only be used on wood and aluminum but we'll see. Many Thanks.