I can vouch for the Oxo. They have flat silicone pieces inside that have holes in them, in addition to just the bristles, and it makes them hold more butter/whatever and work better. In the product photo you can just barely see the flat pieces in the middle, but IMO they are what make this brush work better than other silicone brushes.
Clicketyedit to fix clumsy typing
Thanks, I saved this on my Amazon wish list.