Not much for shedding as well, unless you're unlucky enough to get a defective knot. Synths can be prone to a 'doughnut' forming, but it happens for animal hair brushes too.But one cannot help but compare, especially if he succumbs to the hype surrounding the über-expensive badger brushes and wants to try one. The latest gen. of synthetic brushes just flat out work better IMHO. Cheaper (usually), no break in period, will practically lather concrete and one can select any level of "scritch" from sadistic to BBS.
One small gripe of mine for synths, is the majority of brushes seem to be the on the larger side of things, generally all 24mm/26mm plus, and the actual measurements of the knots (eg like with Yaqi) are a few mm's more whilst a Omega advertised as a 24mm knot, will be 24mm.