I love coverage with AT&T, but the call quality is generally pretty bad and I hate their pricing. If I just pay the ETF and unlock my iPhone 4S, I can go to T-mobile and spend half of what I am with AT&T. In this area, I know a few people with the iPhone 5 that get great coverage. My concern is while I know data will be slower on my 4S than the 5 when I switch to T-mobile, how will voice coverage be? Will it be identical?