I completed this repair at the same time as replacing my battery and headphone/lightening jack assembly. The problem I was experiencing with my camera was jittery video and unusable photos. The stabilization gimbal had died, though I am not sure that is the right word for it. It's more like it had an overdose. Anytime I would come to use the camera you could hear a tiny clicking noise as the lens armature shot itself about within its tolerances. Photos were out of focus and jittery, even when taken with the phone completely stable and untouched. I could most of the time just manage to make it take photos to deposit checks by holding the phone horizontally and in very bright sunlight, sometimes tapping the phone until the clicking noise stopped. Videos would hunt for focus and look as though I was actively shaking the camera, no matter what. Sometimes it was worse than others. Replacing this assembly completely fixed all issues.
Wow! That was awesome. It's amazing how easy things can be when they are designed to be replaced! One note though, when I was draining my new battery, at below 10% it would not play sound. I could not play music, or hear phone calls, I could however be heard. After having opened my phone so recently I was worried a connection had come loose or been missed entirely. Once charged to 100% everything behaved as expected. I am not sure if that is normal or not. I could totally understand restricting power use at those levels, but does it? I didn't "enter power save" not knowingly at least.
I just completed this repair, replacing the Headphone Jack/Lightening port, battery and iSight camera all at the same time. I removed everything as it explained in the guide, but can totally see how not removing the logic board would save time and isn't 100% necessary. I imagine that peeling the upper portion of the headphone/lighting port is slightly easier with the logic board removed, and you don't have to worry about that antenna cable. If I did it again, I would probably still remove the logic board.