A major feature difference for T-Mobile customers is that LG G2 supports WiFi calling, but Nexus 5 does not. For those who don't know what it is, with WiFi calling you can make phone calls when your cell phone coverage is not available. Your phone calls will be routed through your WiFi network, enabling you to make and receive phone calls and text messages in deep pockets of the buildings like surgery suites or basements. Wifi calling you won't need custom 3rd party VoIP apps which can connect to you through, for example, Google Voice. WiFi calling has been proprietary feature of T-Mobile phones but they have already made the WiFi calling algorithm open source for developers, but Google is yet to implement it in its phones which I find ridiculous especially in the light of the fact that upcoming iOS 8 will enable iPhones to have WiFi calling feature.