I really like these phones, and I had the Galaxy s Pro (EPIC) on Sprint. Luckily they have the 30 day return policy. I got it when I was on the road, and had great service all over the SW US. When I got home though I had there 4G service in most places locally except of course at my house. I could get wimax 100 yards from my house, but almost no service at my house. Just so you know it is the same with Verizon (weak signal, but I do get service), and At&t ( my brother has a iPhone 4g). So I am a contract less cellular floater, which of course is not necessarily bad. Either way I love the Epic, and this one is BETTER, with an upgraded display so it is one I would definitely buy, if of course I liked the provider I could get it with. As far as that goes I do not know about T-Mobile.