Downloading from the web is currently extremely slow.
We lost Google Maps for more than a week and then it reappeared.
Voice calls from our main location and other locations in our area is pretty bad. A friend's iphone worked fine in a restaurant we were at. Ours didn't work at all. Couldn't make voice calls. Didn't try the net. He had an AT&T iphone contract. We bought our iphone 4s at full price at an Apple Store.
Data connection was down from our main location for first 3 weeks we used straight talk. Then it came up. I believe we are now almost at the end of our second month.
Why all these problems? It has been an extremely disappointing experience.