@Martin Fowler
I'm not sure what cells you hang about in Martin, but I've been with Orange for years, and I've had no problem with coverage or customer service.
At work my boss is an avid vodafone fan, and all company mobiles come from vodafone. I've lost count how many arrive either misconfigured, or not configured at all. Message centres not set, WAP/Internet access points incorrect, and the pain of actually trying to speak to someone who knows what these setting should be in unbelievable. I know, cos I'm the poor bugger who has to do it.
I won't mention the crazy things that the vodafone internet gateway does to http request... Lets just say when you write a java app that uses http requests, you really don't want it to go via vodafone!