My phone would need to be charged at least 2-3 times a day with moderate normal use. There were times where it would shut off completely with 50-80% battery life showing. Very hard to rely on a phone under the conditions so I purchased the battery fix kit from ifixit and could not be happy with how it turned out. The phone works beautifully again, and now holds a charge for about a day and a half with moderate and normal use. Very satisfied customer here!
Went very well. The one difficult part of the install is getting the tiny screws to seat right when installing them back but i believe there were only 5 or 7 total and it was definitely manageable. It seemed overwhelming at first but turned out to be quite simple.
Go slow, take your time, and follow the instructions or youtube videos closely and it should go well. Take it one step at a time, do it in an area with good lighting, and also establish a place to put VERY tiny screws so you do not lose them. I dropped one on the floor and thought it was gone but a magnet was able to help me track it down. Go slow and it will be a lot easier to manage.