4G LTE or 3G
I'm looking at an iPad and want to get the ipad retina with wi-fi 4G but currently don't have 4G service in my area, Verizon said they will be expanding soon to here. Can I set the iPad to only use 3G until 4G comes and toggle back and forth when in a 4G area.
It will automatically drop to 3G. I don't think you need to do anything assuming you want cellular on. But you can go into Settings, then Cellular Data, and click off on the Enable LTE button. I'm not sure what good it will do you though because if there is not LTE service, you're not going to get connected to LTE anyway. One possible advantage to leaving it on, assuming you have cellular on and have a plan, is that you will know immediately once it becomes available because you will see "LTE" at the upper left portion of the display.
In the "droid" world, it makes a difference if you leave the 4g toggle on. If there is no 4g available, the phone will automatically drop to 3g, true. But the 4g radio will continue to "hunt" for a 4g connection and this consumes a lot of unnecessary power. In 3g only mode, once the radio syncs to the 3g signal, power usage drops to standby mode. That of course is in the droid world like I noted. But I toggle my iPad 4 and my droid phone to LTE (4g) when I know I'm in a known 4g area anyway. I have no iPad empirical data to support that, but it's a habit I had to learn with the phone.