fineartvideo

Magicjack is as reliable as your internet connection. You'll need at least 512K upload speed for this to work well, but more speed allows it to work well even when other devices are sharing bandwith. If your audio starts to break up, it's a sign the internet speed is too slow due to another device hogging too much bandwidth. 256K is the minimum, but than you can't use any other internet device while making a call.
The newer devices work with or without a computer. Without a computer, you need the included AC power pack. But you don't need the AC power pack if you use a computer. The USB port has enough power to operate the device. An added bonus is if you use this with a laptop that has wi-fi, you can bring the magic jack and a phone to any place that has wi-fi and make free calls without plugging cables into power or internet. There are still places in the country where there is no cell service, and this fills in those gaps as long as you're not moving around.
An added bonus not advertised is the ability to use the same phone number in two locations, provided you have two magic jack devices. That means home and office can share one number, or switch to separate numbers when needed. In addition, you can download an app to a smart phone or tablet and that will also share the number when it's within wi-fi range.
Very few services offer free calls to Canada and the US, so if you have people in both countries the calls can all be free with your cheap annual service fee.
Setting up a new device to run on a new magicjack number is simple and fast. But if you need to port in a number, it can be a hassle. As good as the technology is, the support service sucks. And there are no phone numbers to call. You're stuck using a chat service that can take half a day. And that's if you get someone who understands your problem and can figure out a solution.
Bottom line is this. Magicjack makes an excellent inexpensive landline service for people who otherwise would only have a cell phone. Cell phone service can be weak, batteries can die and phones can be lost or stolen. Thirty bucks a year is darn cheap for a backup or second phone line.