These brushes are so handy! I have a couple of small round waterbrushes like these for traveling (Pentel and Sakura brands, both of which are quality brushes, too), and I really wanted some different sizes for working on larger paper. The variety of brush tips that come in this set are really great to work with. My favorite thing about these is that when using them there isn't any need for dirty water cups to mistakenly drink out of! XD
So far I haven't had any issue with these brushes. They have clear/white nylon fiber bristles, like my Pentel and Sakura brushes. Unlike my Pentel and Sakura brushes, these take a bit more squish to get water out of the brush, but it's something I feel I can overlook and doesn't affect my work.