Which is better? Magic Jack? or Google Voice? to make free domestic U.S. calls...

Both Magic Jack and Google Voice seem to be pretty good VOIP phone services. I noticed on Ebay there are phones specially suited for Google Phone, which is currently free. And Magic Jack is already plug-n-play compatible with any current land phone.

So is there a good reason to go with one over the other?
Please don’t direct me to any tech-heavy computer geek methods of free VOIP. I want something that is intuitively useable to someone who hates complicated processes.