It depends what you're trying to do. If you're streaming video, you're likely not going to get any carrier to work consistently. On the other hand, if you're checking Facebook, you're mostly loading content and then reading it, so you don't notice your signal strength going up and down as much. A lot of what people experience will have to do with their phone and the number of people connecting to the same cell site. I've been standing next to my sister, who also has Verizon and only one of us gets a good connection. And I've been standing next to friends with AT&T and we both get the same level of service. As far as WiFi, you have to decide how much you're going to depend on it, measure that against the limited area of availability and possible overload of users. If not being able to connect is going to cause issues with your trip, then consider an alternative data plan.