So I had my battery out of my phone for something last night and I noticed that my Sprint S4 has a sim card. None of my previous other Sprint phones had a sim card. I'm guessing this is for the 4G LTE? Does the Sprint S4 have CDMA and GSM radios in it? Why I am soo interested, is that I travel to the Philippines at least once a year and they don't use CDMA over there so my other Sprint phones never worked. I'm guessing if Sprint will unlock this phone or I root I should be able to use a Philippine sim card and use my phone. Yay? Nay??