Actually, building on what Dan Kap said, ATT you can change your data plan whenever you like during the billing cycle, and they will apply that retroactively if you have already went over your data. I don't know if other networks do this, but I have used it myself. After approaching going over my 200MB for about the fourth time in a row, I upgraded online retroactively to the 3GB plan without penalties for that particular billing cycle.

I don't know where the real 4G LTE markets are and where they are not, but I live about an hour north of Philadelphia and use 4G LTE. I'm not sure if it is my newer phone with a better processor, the 4G LTE network or a combination, but I can download and install an app in less than a minute. That is much faster than the previous download times on the 3G network, if that helps anyone's decision, at least in the Philly area. I went from an HTC Aria to an HTC Vivid.

I've been thinking about changing carriers, but I feel like at this point, they are all sneaky, none of them have the customers in mind and you can't win, which is why I stay on ATT. I had a bad experience with Nextel when it was in the process of being bought up by Sprint but kept its name, and I have had frustratingly spotty and shoddy "service" from Verizon home products, so I never bought a cell through them. I've been thinking about Tmobile, but what's the difference anymore? I hear prepaid plans are getting better and better and the phones that are being offered through some of them are more up to date than ever before. Who knows?