The only bad point with three is the Customer Support, its mostly based in india and they rarely hear what your saying.
because the uk based CS from the others is actually better?
granted the indians are horrible and make you feel like a monster for cancelling anything but they dont usually make me want to go burn down an EE or Voda store any time i ever have to interact with them
I said nothing after the hassle porting my number over. Porting problem was Vodafone end and not EE whom I was porting from.Actually on this topic does anyone know is EE changing all of its branding to BT Mobile or does EE remain as it is now?

My work phone is on Vodafone and personal phone on O2.
I have to say that Vodafone is terrible for me. I go round the UK in my job as a consultant and generally have nothing but frustration using Vodafone. Mainly Internet connection being poor with it dropping back GPRS or Edge and some time no data at all. I could understand this if I was out in the countryside but not when working at Canary Wharf or other parts of London. Vodafone is generally hated at the company I work at. Phone calls can drop out more as well.
I don't generally have these troubles with O2.
Voda have done a load of network upgrades in the last month or so - loads of places have gone from getting Edge at 80kbit/s to a fairly consistent 3G/HSDPA+ at just under 7.2Mbit down (I assume they are using whichever standard it is that is 7.2Mbit) and just under 2Mbit up.