If the person is having problems on Skype and it is due to an older computer or slow Internet Connection, Google Hangouts will freeze a computer. I know my old computer worked fine with Skype but Google Hangouts froze my entire system.
Although you could use Google Voice to make calls which when I had problems with Skype worked fairly well. I use both and have very little problems now, but your computer system and Internet Speed have a lot to do with call quality.
It is possible if you are having problems with a certain area the call quality could also be on their end.