The reason for only 4 stars is that they are a little more spendy than the other guys. Then again, you get what you pay for. I have never lost a call (even when I was in Alaska). The coverage is wonderful. They don't have a lot of plans to choose from, but then again that is less complicated that way. They do offer all the basics: prepaid, local - country-wide service, and family plans.
I have been pleased with the customer service, but I haven't had many issues with the phone/service, so all in all they are above average in my book.