Bookerly is much more bookerly than the old Kindle typefaces.
Plus, the Kindle has a new layout engine that "introduces better text justification, kerning, drop caps, image positioning, and more." Boing Boing alum John Brownlee reports for Fast Company:
After almost eight years, Amazon's finally starting to get e-book typesetting bloody right.
Previous to today's update, when you read an e-book on the Kindle, sentences were fully justified. In other words, no matter how big your font size, Kindle's invisible software always laid-out the page so that the left and right margins were completely straight. And it was ugly. Words were never split across lines, so there could be as many as half-a-dozen spaces between words.
Printed books just don't handle typesetting in this way: they fit as many words into a line as possible while maintaining the spacing between them, and they aren't afraid to either break a word in half to hyphenate it or to leave a gap at the end of a line.