Moved over from a 4s, first experience with Android and have to say was NOT impressed with the camera at all when I got this thing a week ago. After experimenting with more camera apps than I'd care to admit, I decided the problem with the images coming out of this phone has everything to do with the software and not the lens. To me, the stock camera app that comes with this phone is the worst offender, it sometimes seems like the stills are frames pulled from the 30fps video resolution rather than something optimized for stills.
Of all the apps I tested, Vignette did the best job of generating out of the box images that befit a phone of this level. For anyone who's used the app, this is disappointing in one sense in that Vignette is the most paired down camera app I've ever used, the shooter has almost no control over focus or exposure. Yet, after using this thing for a week, I've grown to appreciate the scaled back approach and the images are about a thousand times better than what I got with any other app. See below.
IMG_0056 | Flickr - Photo Sharing!
IMG_0100 | Flickr - Photo Sharing!
IMG_0058 | Flickr - Photo Sharing!
It's not perfect but for me, with what I want to get out of a phone shooter, the images you get out of Vignette are a much better starting point than the stock app and doing some subtle color correction/contrast/brightness adjustments can help this thing get images very near to what the iPhone gets.