Personally, I think it's a crap foundation brush. The bristles are really flexible and far apart and I prefer my bristles stiffer and densely packed for a foundation brush. Not stiff in a scratchy way, stiff and aligned into a good shape. I got the pret-a-porter brush set for christmas and was excited about the 187 and tried using it for liquid foundation since it is a miracle brush, but it wasn't that great at all and held too much product (product that didn't transfer to the face), and hard to clean - i don't think the 187 holds up that well under over-cleaning, which is necessary if you're an MUA. the 190 and most foundation brushes are made with synthetic bristles which are better for placing foundation straight from the brush onto the face with minimal product loss and little/no streaking and even application. + you can clean them realllllly easily. once I started using the 190 i never turned back.
for powder foundations like mineral foundations it's a passable brush, but i prefer one you can buff with like the 180/182. the 187 is a good face brush for powder highlighters and some blushes, preferably sheer, shimmering blushes (MSFs, for example). I prefer my blush brushes and angled contour brushes for application of most cheek products cause it allows for better sculpting.
i think the 187 is best for cheek products you don't want to over do-it on in terms of pigmentation (think frankly scarlet brush) or shimmer, however, you do compromise on control and precision when you use it - since i've become a freelance MUA i rarely use the 187 and opt for the other brushes I mentioned. the 188 is too small for cheeks, too, IMO. stupid brush. When i want just radiant, glowy cheeks for whomever with minimal sculpting it is great though. hth!
