Uh, is that just a kneejerk feeling of "there is more wasted space" vs. the reality? Because I did get an initial kneejerk "shove this mobile the fuck out of my desktop" reaction when I tried the new design.

But I checked, and the tweet boxes themselves are a bit wider and a bit taller in the redesign. Even so, though, I can see just as many text-heavy tweets on screen with the new UI as with the old one because the UI itself wastes less screen real estate - and that's with the second-smallest, default font option. The same applies to tweets with heavy picture use: I can see a larger portion of a chopped-off tweet with the redesign than I can with the old desktop UI. With the smallest font size option, it's not even a contest and the redesign wins handily.