We just got 4G in Miami, and I was wondering about how turning this feature on will affect battery life on my Epic. How much more battery power is needed to drive the 4G versus 3G? Suppose I am in an area with a weak signal? Does the phone try to connect repeatedly if I lose the signal, draining the battery that much more quickly, or does it only try to connect at a reasonable enough interval that the battery drain won't be such a big deal? If 4G turns out to be a power hog, do I even need it for things like regular cell calls, or should I just reserve it for downloading/uploading files? Honestly, for most of what I am doing (calls, texts, satellite radio, occasional app downloads), I am not really even seeing much of a difference with the 4G turned on. If it really drains the battery, when does it make sense to turn it on or leave it off? Is there a good app to test speeds that anyone can suggest? Looking for something to verify 4G connection, and to compare speed to 3G. Thanks.