Moved to EE from 3 in June for exactly this reason, with my phone loafing along on the slowest international networks while others had flat-out 4G.
Not regretted it at all - speed tests give upwards of 150Mbps, and even better, the issue of network saturation in big cities and total failure around the south side of Heathrow has vanished.
Biting the hand that feeds IT
