What is the difference between 4G and a 3G connection? It turns out there is quite a bit.
While 3G was designed to offer download speed of up to 3.1 Mbps, 4G is designed to be as fast as optical fiber: so up to 10X faster. 4G also offers QoS support, like land-based data networks. QoS means it possible to vary priority levels for different data streams.
Quality isn't all that important in an email, speed is the only factor, but quality matters when you are watching a show.
Via: 4G Internet