Interesting point but three only generally have 3G enabled with no fallback in urban areas. The only time I see 2G is when I'm out in the sticks on a train. I don't think any of the lte cities will have a 2g fallback enabled.
No, I don't see three enabling any 2G sites, that would be a backwards step for them.
Do phones display or have a state available for showing data coverage with no voice?
No, they all currently use circuit switched fall back to jump from LTE to 3G or 2G automatically and transparently.
As Three don't have any 2G, and 3G in building penetration is lower, this *could* be why they are last to roll out.
It would be interesting having someone with a good 4G signal, being unable to make a call
James BT Infinity 2
19/09/2012 - Sold 42/6 - Getting 46/8 - Sync 50 / 9 Mbps @ 470m approx
14 years of broadband (ntl: cable to BT FTTC) - Router: Asus RT-N66U - Modem: Huawei HG612 speedtest