The 3GS auto switches as well, but you have the option to essentially disable auto switching by turning off 3G all together.This is good news for me as I've had to turn off 3G on my iPhone 3GS to get bars. I've read how the 4S switches so I imagine that's why the option to turn off 3G isn't needed on this model. I look forward to improved signal performance with my 4S that's on it's way to my door![]()