1 bar 4G LTE at home in Philly with download speeds at 1.05 Mbps. Customer service says that one bar is enough. When I had AT&T I had full bars and around 25 Mbps! I'm using the iPhone 6s...is there anything I can do, besides switch back? I've restored the iPhone, reset network settings, reset all settings, replaced the phone at the Apple Store, not sure what else can be done. Any ideas? Thanks.