Originally Posted by Josh-SEAnswers
The "i" version should work fine with T-Mobile. The "a" version is the one we would recommend to use with AT&T and they have different 3G frequencies than T-Mobile. So for T-Mobile we do recommend the "i" variant version of our phones.
With the "i" version can I get a US warranty? And with "a" version can I not roam onto AT&T's 3G even though I'm on T-Mobile?