Like any four-year-old, EE's 4G network hasn't yet fulfilled its potential. For its last major upgrade, the carrier flipped the switch on Cat 6 LTE-Advanced two years ago; and today, EE has announced it's begun rolling out even faster Cat 9 technology (the first UK provider to do so, it seems). This increases the maximum theoretical download speed on EE's "4G+" network from 300 Mbps to 450 Mbps, though real-world testing puts the max at more like 360 Mbps. The catch? Only a handful of phones can take full advantage.