I love this brush! I've never had a duo fiber brush before, and it's really great. I use it for blush and my MSF.
Studio Tools make really great, super affordable brushes. I have the smudge brush (great for smoking out eyeliner), the angled shadow/liner brush, and the crease/contour brush, which is one of my favorites. I find their eye brushes to be much better than their face brushes, with the exception of the duo fiber. Their kabuki brush was too stiff (I prefer Eco Tools' travel kabuki) and the bristles on the face brush weren't soft enough.