I have both Verizon (mifi) and AT&T 3G data plans, and AT&T's 3G is a lot faster than Verizon's 3G data when I compare speedtests in the same location. I thought of doing the switch for data reasons, but I know how slow Verizon's 3G can be... so I wasn't sure if I wanted to be grandfathered in Verizon's 3G data. Also, I am also speculating that when Verizon get's a 4G LTE iPhone, they will probably NOT offer an unlimited plan to upgrade to 4G LTE... if you want the LTE iPhone. I think that AT&T will probably do the same when they get their 4G iPhone. For now, since I don't know the future on data plans.. as they upgrade to 4G, I am basing my decision on what gives me the best phone coverage, and Verizon has a poor phone signal where I live... but Verizon has great 3G data coverage. Sometimes I do like to use my iPhone as a phone.😉