The difference between 3g and 4g is the speed in which you can download data. This is noticeable on a mobile phone primarily during activities when you are using an application that needs a lot of data (like watching videos). However, 4g networks are not as wide spread as 3g and you will sometimes find your phone dropping back to 3g when 4g is not available.
First, please don't go on saying that any one particular carrier sucks and all that fun stuff that tech trolls love to do. We all live in different areas and the carrier with the best coverage varies for all of us.
