Okay, I've had every model of iPhone since the original in 2007 (except the 5C) and have been on Vodafone for almost the entire time. For the 3GS in 2009/2010 I did use O2. Now I've had enough of Vodafone, their 4G is actually pretty good (London). But they're calling quality for me is terrible. And more importantly, I don't work for them anymore so I cease to get any discounts with them. I'm thinking of changing network next month. It's currently between Three (price) and O2 (quality). What networks do you all use? How is the 4G? Does anybody have any experience with 4G on Three? Also what area are you using your iPhone in?