Yep, I got the 64GB black one. I can't recommend it enough. The only downside that I have found is that it's not MHL enabled, meaning that I can't attach it to my TV via a USB to HDMI. I fancied doing this to watch the Ryder Cup and the odd football match with a sports streaming app I have.
The battery is incredible. I can get all day, plus a night shift on a charge and that's using it for all sorts, everything switched on. It charges from 30% (the lowest I've had it at) in about an hour.
As for 3, I signed up for a rolling 1 month, 4GB or data sim only deal after years on GiffGaff. After a week I had less than 2GB remaining so I've changed it to a 12 month, unlimited data deal for £18 a month although I think that has gone up to £20 now. I was a bit hesitant about the 4G as some stuff online says only in London and Manchester at the moment but rolling out across the UK through 2014. Well I've had and 4G at Sheffield, Leicester, Derby, Long Eaton and can get it outside my house 6 miles out of Sheffield. I was somewhere the other week (can't exactly remember) and got 20mb/s on 3G HSDPA+. The 4G tends to be between 6mb/s and 17mb/s.