-Circumference of the flat top part of each brush is the same size.
-The way they buff liquid foundation on is nearly identical.
-Neither brush sheds at all.
-Both are synthetic.
-Bionic brush is an inch shorter.
-Bionic is denser with the amount of hairs, but not by a large amount.
-Bionic is softer against the skin.
-Bionic is firmer.
-E.l.f. brush is jiggling loose already from its handle, but it does not bother me.
-Bionic is 13.95USD and E.l.f. brush is 3USD.
Overall, the Bionic is the brush I reach for the most, but if you are looking for a VERY similar and much cheaper alternative go with the E.l.f. powder brush.