But in your original post, you say you have a 2G iPhone. I am on AT&T, have been for oooohhhhhh, let's see......12 years or so. I, too, have not had the problems that I have read on numerous forums.
AT&T coverage is just like other carrier's coverage, sometimes it is hit and miss. You may get more bars from T-Mobile in your house that AT&T, who knows.
Try someone's AT&T phone in your house to see if there is enough signal to warrant the change. Switching carriers to get the newest phones don't matter if you can't use them.
