I went into a local vodafone shop and had a look at the 6 and 6plus in person. I am absolutely no further at deciding what to do. I think the 6plus is just too big, especially with having a 3G iPad mini. But the better battery life and camera are still pulling me in that direction slightly. The 6 looks absolutely perfect, a nice size, a beautiful screen but those two factors it is lacking.
On top of that I'd want to stay with Three and for my current contract it would be £50 a month and either £29 up front for the 64gb 6 or £99 for the 64gb 6plus. Which is an unbelievable amount of money.
The price between buying outright and that contract for the 6 is £130 cheaper to buy outright and £120 cheaper for the 6plus.