Who are these lucky people for whom 4G works half the time!?
The only places 4G - or mobile web access at all for that matter - works for me is pretty much inside an O2 shop.
Anywhere else - central London, Greater London, in the country, in my house, in other city and town centres - no chance. On the train - ha, that's a good one.
I'm still not entirely convinced there isn't a problem with the 4G hardware on my iPhone. Been in a O2 shop twice now to check it - as I say, works fine in their shops, but hardly anywhere else.
Discussed it many times with O2 online chat support. Oh boy, what a frustrating experience. ("Support: Please reset your network settings on the phone, then Internet will work. Me: My problem is not that it doesn't work - it's just slow [ bangs head on wall etc ] ")
Never did get round to taking it to an Apple store to get it checked - always felt Apple would say it was O2's problem.