Ill be honest and say the battery life in mine is a little pants. But, for what I want its perfect. Call quality is good, even at one bar Ive found. Reception is an issue for me, but it is a network issue rather than phone problem (Orange send the signal out on a set frequency that dosent like old houses or thick walls, same with T-mobile) The phone surfs the net very well, esp with WiFi.
Worst thing is its too reliant on I-tunes, has limited personalisation compared to Google Android, cannot transfer photos taken on the phone to computer without a paid for app, cant back up contacts to sim card, has rubbish battery life and everyone around you goes 'look at you with your Iphone'. Ill forgive all this to have the best quality music player on the market (out of a phone) by a long shot. Some people hate it until they play with one, and until they play with one they dont realise its actually a smart way to work, but people dont like change. As we are the underdogs being British, we often prefer to head with the less popular brands. Surprisingly though I think Nokia have the largest worldwide market share, followed by RIM (Blackberry) and Apple/Google Android following up but it changes so much dependant on the website you read.
CountZero, to be picky its the Iphone 4. 4G dosent technically exist in the UK yet and the Iphone 4 only runs off 3G signal. I think Switzerland has the first full 4G network but its only a matter of time til we get it. It basically will offer faster and more secure internet, making things like mobile banking and augmented reality a sure thing.