Nope.. I used to use it when it came to my area. Before that I was using Cricket - http://www.mycricket.com/ and I am using that service again because they dropped their prices.
The only downside to them is they are local only. You cannot use them once you've left your immediate area. It works fine in your home town and maybe a couple towns around it then it cuts out. I believe you can buy minutes for traveling outside the area and it works like a pre-paid phone.