A:AnswerIf it's truly global unlocked then yes you can use it anywhere on the world... If it's just regular factory unlocked then it has to be still in North America only
A:AnswerUnlocked should work on every provider. GSM or whatever you call like the Verizon and sprint phones doesn't matter anymore. But don't quote me on that.
A:AnswerYes I purchased an unlocked phone directly from Samsung and put a Spectrum sim card in. I have some issues getting voice mail notifications but I am not sure if it is a Spectrum issue.