So I've been thinking about this more since yesterday. I think some people misunderstood me and thought I was saying that pixel-perfect and polished designs are always necessary. They're not. Sometimes fast and sloppy UIs are what you need to build in order to learn the fastest, and eventually get to a better product. (Sometimes misaligned elements and odd typography gets the brand tone just right, like on hacker news.)

The part I haven't quite figured out how to think about yet, is how teams decide how much the details matter. How do you know when the fit and finish is good enough? I'm not sure. I do think though that as products are competing more on experience (easier, more delightful, focused, etc), that the details will matter more than they ever have in the past.