Reviving a dead thread.
I have been using VOIP for about 8 years. Just switched to Magic Jack. Quality is a lot better then the service I was using though still not as good as traditional land lines. My brother had been using it and loves it. I jumped in all the way upgrading to the 5 year plan. Including shipping, regulatory fees and what not I am paying $4 a month for service but it was prepaid so I will not have a phone bill for 5 years. Called my wife and she said it sounded much clearer then our VOIP phone service ever has.
As far as people complaining about them not working, from everything I have read is if you have an old, slower computer and do not have a fast internet service then it will not work. In about 5 days when the porting of my old number is complete I will cancel my other service and save $35 a month. (Yes sadly the price started out low but has crept up over the last few years.)