So I'm back with Vodafone. It's been a while. Not since my fault prone Nokia N95 8GB days (I sure do pick the troubled handsets)..
I must admit they have an amazing number porting system (linked below). I did have to give them a quick call to find out my new account number but that was trouble free. The IVR options need a bit of work but after a very short while I got through to someone who answered all my queries in one go!
I did previously like Tesco mobile (O2 network) but I couldn't see an offer to suit me for what I wanted at the time). Also O2 didn't do as well as the others in the 4G auctions in my opinion, so it'll be interesting to see how they do in the long run. Then again I think Vodafone want to re-contract everyone onto 4G contracts when their network goes live (with big early termination fee discounts for current customers in contracts).