I like the big play/pause button and the big 30 sec. back button. Those are the buttons I use most often. I don't care for the big bookmark button, though; I never bookmark audiobooks, since they start playing where I stopped reading. Perhaps some people use them though.
I don't really care for the "information" button in the upper right - I don't think I'll use it that often, so why give it such a prime spot. I'd rather the "chapters" button be there; that's where I expect it.
I like the additional options for narration speed. I wish they hadn't bothered with "button free" (I thought this about the last version, too). Who uses that? My phone is usually in my pocket or someplace where the screen is inaccessible; plus the screen is usually locked. I mean, I can understand someone who doesn't really use the app thinking that this would be handy because you can control the device with your hand in your pocket...but in actual use, it's not handy, for several reasons. The most important of which being that you have to take your device out of your pocket and look at to to make sure you're on the swipe screen - and if you've done that, you might as well just use the buttons. (Enough of this topic; it was just as bad on the previous version).
I don't really care for the new "chapters" design (not that the old one was so great): while the (unimportant) chapter numbers are larger, the time in the chapter is the same size or smaller (I can't tell; maybe it looks smaller). Plus, why don't they tell you on that screen how much you've read of that chapter and how much time is left?
I'm happy enough with the chapter forward/back buttons being removed; I rarely used those, and the times I did use them it was because I inadvertently hit it sending me to the next or previous chapter and had to find my way back. Listening to a book is not like listening to an album; I don' think too many people skip ahead to the next chapter like you when when skipping a song on an album.