Hello. I've been with ATT for a few years now and am a bit tired of their high rates for my Iphone service. My current phone is an older 3s, but I am planning to buy a factory unlocked used 4s and take it to TMobile and port my current phone number there as well.. Should I expect any problems or difficulties? I live in New York. Need 500 minutes of talk Unlimited SMS 2 or 5 GB of webbrowsing Tethering for my Ipad. Has anyone in this forum switched? Can you recommend it? Any problems? TMobile tells me that their service is now 3G in most of NY, so I should get equally fast internet as I have now. In January they will have 4G mostly anywhere in NY. Thanks in advance.