My wife is going to be in Japan for a couple of months, and travels back and forth with some regularity, and we're extremely light cell users in the US (I have a 3GS on H2O and don't even use up the $10/month minimum prepaid), so we're considering getting an unlocked 5s so that we could use a month-to-month plan in the US and switch to a prepaid SIM in Japan as necessary. We have no interest in getting a subsidized phone due to just not wanting a large monthly bill and having no guarantee how many of the next 24 months the phone will even be in the US (buying one in Japan would put us in the same boat). However, looking at Apple's LTE compatibility page, it looks like the 5s model we'd really want is the A1453, which in the US is only apparently available from Sprint and not unlocked. I even checked with Apple Store support and they said "no luck". Which limits me to the T-Mobile "uncarrier" version (it's the A1533 GSM one, apparently), which at least seems like it can do what I want with it. Has anybody used that phone in Japan? Docomo's network (who the prepaid carrier we're looking at uses) apparently is GSM compatible on their non-LTE coverage, so I'm assuming that it would just not work at LTE speeds on account of not having the extra 800MHz band on the antenna (in fact, some of Docomo's network uses a non-800MHz LTE band, so it might still work--I had trouble finding info on exactly what bands their "Xi" service uses--they just say "Xi (800MHz)" and "Xi"). I'm pretty sure it'll get at least some functionality, I'm just wondering if anybody has tried it personally yet (or knows more than I do about what LTE bands Docomo's Xi service uses) before I go sinking a thousand dollars into a phone and prepaid plan.