I've commented in previous threads about this. To sum up: My advice is to look at Xperia Compact. It's Android with pretty small modifications from Sony (most you won't notice really, like a bunch of their pre-installed apps). It has awesome battery time, it's small and generally good. It's not top performance, but I doubt most people need that anymore. The only downside is you don't get a top camera (although an okay one - Sony is a camera company after all).