I finally tried my Beauty Powder today and I really like it. Disclaimer: I have no idea what I'm doing. This is my first time using a beauty powder, so take what I say with a grain of salt.
I used it as an all over face powder. I have the 129 brush, but thought it would be too compact for all over use. I didn't want to look like Ashy Larry. I started using the 187 because I know it's meant to diffuse color. The problem is that I felt the bristles were too long to properly buff out the powder and I felt like I had to keep dipping into the powder too much. I switched to my 182 Buffer Brush and I think it worked very well. It didn't pick up too much powder and I was able to buff everything out very easily.
I only applied the powder to half of my face. I liked what I saw, but I'm not able to explain why I like it. I just do. My skin did look matte and brighter. Maybe even smoother, but it wasn't anything drastic. Looking really close into the mirror, I could see tiny little powder flecks. I asked my friend if he thought one half of my face looks different from the other. He was able to pick out the side with the Beauty Powder and said my skin looked more evened out on that side, but that it was subtle difference. I don't know what I am, but I would guess NC/NW 45-50 if that helps.
I like the Beauty Powder and I'm glad I have it, but I would love to have a version for deeper skin tones. I think I was able to make the powder work, but I have to be really careful with how much I apply since it's so light. I didn't try it as a highlighter, but I think it would work fine for me.