My primary complaint about synthetics is that they lack sufficient backbone - except for the Muhle knots. [I do have a FS Fibre shaving en route.] However, I have a hard time with the looks of flat top brushes. For years, all I bought were bulb style brushes. I bought my first fan about 9 years ago. I suppose someday I will try a flat top - but it will take me a while to get used to how it looks!