Coming from the iPhone 5 (last iPhone I used) I was hugely disappointed concerning camera quality with android phones. I had an Xperia Z, Z1 and Nexus 5 (not counting the Droid 4 and Photon Q...those were no real cameras) and every single of them had terrible camera quality.
Of all those the Nexus 5 probably had the best....if, and thats a huge IF, the frikkin camera managed to get a focused shot.
I have 2 DSLR and a Sony NEX7, so most of the time I use those, but I was looking for a decent phone Camera for convenience reasons,
The iPhone 5 had a great camera, then a Nexus 5 and Z1, then the Z (terrible camera). Out ouf 10 pictures, the iphone made 5-6 in focus (those quick shots on the kids you konw), the Nexus 5 probaby 2-3, the Z1 about 5 and the Z with a lot of luck 3-4.
The LG G3 is a decent phone (although not great, I still think of the Sony line to offer the best "Operating System" (launcher etc. is awesome on Sony devices), but the Camera on the G3 is GALACTIC!
Not so much for the quality of the picture itself (its good but I saw better on the iPhone 5 or 5s) but for the speed. For those little snapshots of kids playing (and you know, kids won´t hold still for a second) this is by FAR the best camera. Out of 10 pictures i manage to have 9-10 in focus....I now rarely have to delete any photo because its out of focus. So I would say that the laser focus really makes a huge difference.
Usually the G3 takes the photo the second I press, this is amazing!