When I first bought my Z10, under System Settings / Network Connections / Mobile Network / Network Mode it gave options stated in terms of "G", i.e, 4G or 4G & 3G & 2G, or 4G & 3G etc". After installing one of the leaked OS's (I think 10.1.0.2342) these options changed to LTE/UTMS/GSM etc. Now suddenly they have changed back to 4G etc. What was nice about the LTE/UTMS/GSM options was that you could set the phone to GSM only so that the phone was restricted to 2G. There is no such option in the 4G 3G option version. You cannot turn off 3G, which is a big battery user. Setting it on GSM only (2G) used to give me a good few hours more battery life a day. Do you have any idea what caused these changes? Is it OS version related or is it a user setting somewhere?