Daniel Jalkut:

For many of us who make, use, or write about software for a living, polish is all about removing from the software as many jarring behaviors as possible. Sweating the small stuff. It’s exactly the details like the persistently stuttering scrolling that MG points out that continue to make Android products appear less polished to us. It’s seriously unnerving. It’s a big freaking deal to us, while other people just don’t see it.

That split-second delay from when you flick to when it gets flicked. Once you notice that, stuff that has that is no longer good enough.