Tried it over the weekend. So far, so good. Data turns to edge as I turn off the screen, and back to 3g when I unlock my phone. I have gotten about 50% more battery life because of this tweak. But the downside is... If you constantly text, and turn your screen off and on, the phone will constantly turn from edge to 3g making the phone do that all the time... It does mess with the battery, but in a good way. I constantly use my phone during work (no wifi at my job so it switches off and on), and by the time I leave, I usually have about 20-25% battery life left... But with this tweak, I have 50% when I left. I would say it works. I have a 4s btw