So, I bought the Galaxy S4 for straight talk with the AT&T compatible sim and surprisingly I got amazing service. But I missed having an iphone so a few months later I bought the iphone 5s with an AT&T compatible sim. The service sucks! I wouldn't even consider it 2g (it says I have LTE with full bars) it can't even load a basic webpage without taking 10 minutes. Should I try a T-Mobile compatible sim and hope for the best or just give up and switch back to my galaxy (which I don't want to do)?