Well, I also have an iPhone 5s, and it also gets EDGE in the same areas where the 4S gets EDGE, so it's not the hardware or lack of frequency support.Their reframed pcs 4g is nowhere even close as good coverage as their aws band. Going from a non aws iPhone 5 to aws iPhone 5s was a night and day difference for me as far as 4g coverage.
We have a few more days before our return window expires, but unfortunately we are most likely going to have to cancel service with them. We can't keep paying while we wait for them to improve, when AT&T is better for us right now. We really wanted to like T-Mobile. We'll how their coverage is in a few months.