The s5 definitely takes a great picture in well lit areas. It's the darker areas that it has trouble focusing and stabilizing the image. As for comparison, I was just using my old iPhone because I was getting sharper pics more often on the iphone and I couldn't figure out why. Now that I understand the camera better, I know what to expect.
Now that being said, I don't know how the quality of a newer iphone would compare. The 4S is 2 generations behind. I'd be curious to see some photos from an iphone 6.