Ring signatures are better than master nodes. It is better to look under the hood and try to understand how it works. I am not a technical person but a quick google search and 2 to 3 hours of reading all the articles and comments from each side it would be easy to see which is better. The answer is right there in front of you. I also did not know that research and implementations of ring signatures started on 2001. It was wise for the Monero development team to use it in their cryptocoin to find answers in unanswered questions since 2001.