I used to be a Juice Defender fan, until I realized that saving power is worthless if it makes the phone unusable for its intended purpose. I had constant hangs, missed messages, network not available when I needed it, etc. If I started disabling the features that impacted me, then it didn't save much power. This would be like adding a device to your car that doubled your gas mileage, but then the AC would not work right, it would frequently stall while driving it, the radio would randomly work at low volume or full volume, etc. If you defeat the purpose of the thing for one benefit it isn't worth it. Juice Defender is like being a miler, those annoying folks who will do anything, including breaking the law, risking safety, and holding up others - just to save fuel.