Battery life really depends on how people use it--things like if WiFi is always on, if the light is always used when reading. I expect the page turning to be faster. They are talking about a different technology for it, and it is not like more than 1 GHz is required for that. I know that in the past, speed for that kind of thing has improved greatly as the developers continued to work on it. It has not been a hardware issue for a very long time.
The Aura is about an inch wider and two inches taller. I ordered one and will report back on how it feels in my small hands. I did not get a cover. if that oddly shaped back is supposed to make holding it a better experience, then I didn't see the point in going for a flat backed cover. Besides, they are saying that the screen is much more durable than previous models and I don't expect to take it out of my house, except when it goes away on holidays with me.