After hearing all the raves on the MAC 187, I decided I wanted to try a Duo Fibre brush, but didn't really want to fork over US $42. I got this one from China but they labeled it as MAC 187. The seller told me that this is more of Coastal Scents Fibre Optics kind.
As for the quality, this brush have a bit of fall out the first couple of times you wash it. Along with the dye running out every washing. Although the brush still performs well despite of the cons. The brush is very soft and the bristles are not very dense. It's great for light and even application for foundation, powder, and blush.
It gives me that airbrushed finish.
Since this is quiet cheap, I always handle this brush with care. I use shampoo for cleansing and use a bit of conditioner to keep the brush soft. I always keep the shape in tack and have it air dry.
Overall, this is a great brush for somebody who's on the budget. It's not comparable to MAC 187 "the real thing" but I'm in no rush to pay the massive price difference to find out.