I noticed that the WiFi reception on my iPhone 4 suddenly decreased without any possible cause. I spent some time changing settings on my router at home without success and noticed that my other devices in the home would have excellent connections while my phone had almost none.
The repair was simple and straight forward. It was very easy (and cheap) to get the directions I needed and pick out the parts & tools necessary. I especially appreciate that iFixIt made clear how the 7 screws needing to be removed were of 5 different sizes. The repair took 10 minutes and I now have regained the WiFi experience that I expect with the phone.
Make sure that your read the instructions all the way through before you purchase any parts and also read it through before you start the repair. It will make things much easier.