I spent quite some time checking foundation brush reviews online... did not find much info about this one. I love Clarins so I decided to ignore my field research and give it a chance! I am certainly disappointed. Not a great coverage, not a quick brush. It leaves streaks on the first passes, what forces you to really make effort on smoothing out. It does not also master at spreading the foundation. It is easy that the end product is not homogeneous when "in-a-rush" morning.
On the positive side: it is extremely soft, which feels nice, but it would be great if it would do the work better.