reply to ArizonaSteve
Re: Formerly Unlimited (really) 3G card I used Millenicom for several years and had no problems stopping the service. All I had to do was send one email to stop the billing on my CC account.
You will be on the regular Sprint or Verizon data networks, the same as if you were a direct customer.
Most of the problems I see posted on forums about Millenicom has to do with a local Sprint or Verizon tower. In other words if you are getting poor speeds on your local cell tower Millenicom can only report the problem to Sprint or Verizon. After the iPhone was available on the Sprint network my local tower was next to unusable for a data connection. On the other hand in different areas people report very fast speeds, the same applies to Verizon.