I've had a MJ for over a year now. No complaints but I don't use it as a primary phone line. I use it when I travel. When I am in Europe I use it to call US numbers. Just plug it in to the laptop and if you have Internet access, you can call any US number for free, no mater where you are in the world. I use Skype too, but the MJ is cooler. You kind of have to be at the computer to get a Skype call. Not so with the MJ. I bring along a small telephone and plug it into the Magicjack and just leave the laptop turned on. That way it rings and acts like a regular phone--but with a direct connection to the USA. People who call me don't get toll charges either since they are calling an LA area number. I also like that when someone calls and you are not available, they email you a recording of the voice message the person leaves.
BTW when I got mine a year ago they said they would soon be able to move your existing phone number to the MJ. Sounds like they are still saying the same thing a year later.