Personally I don't see what all the fuss is over Bookerly. It is just a slightly modified Caecilia. I'm hard pressed to see much difference on my iOS Kindle app. They look nearly identical to my eyes. On the iOS app Bookerly has better spacing between words, but that is because the iOS app doesn't have Caecilia Condensed. I bet Caecilia Condensed will still have better spacing than Bookerly on actual Kindles, assuming they leave it on them.