Need some advice. I'm interested in getting the LG G3 (currently have a Nexus 4 and love it) but not sure which variant to get. I see talk of several different models 850/ 851/ 855. I'm using T-Mobile (HSDPA+ w/ Nexus 4) and want to make sure I can take advantage of 4G LTE and WiFi calling. Does the model matter? I see the D855 is the more popular on most forums and online. Thanks!