I have the T-Mobile/AT&T Developers Edition of the Moto X. I've also got very poor signal strength inside my apartment. Does anyone know if the T-Mobile Cel-fi unit will work with an unlocked phone? I've seen a couple of threads that seem to indicate the answer is no, but no official word. I'm not getting any more bars than before the free celfi arrived, so my feeling is that there's nothing I can do unless I get a carrier specific phone.