From The Washington Post: “Google is manipulating browser extensions to stifle competitors, DuckDuckGo CEO says.” Of course that can only happen if you’re using Chrome.
The new design is flatter; tabs are a bit taller and have sharper corners, and then there are those blue URLs. But it’s easy to get the old look back, at least for now.
The extension’s developer Raymond Hill says that µBlock uses significantly fewer resources than AdBlock Plus. That’s certainly the case on my Mac. Your figurative mileage may vary.