Assessing Portfolio Performance with Risk-Adjusted Measures

John is a portfolio manager who has been analyzing the performance of his investment portfolio over the past year. He is particularly interested in assessing the portfolio's returns relative to the risks taken. To do this, he considers three different risk-adjusted performance measures: the Sharpe Ratio, the Sortino Ratio, and the Treynor Ratio.

John's portfolio generated a return of 15% with a standard deviation of 10% and a beta of 1.2. He also notes that the risk-free rate is 3%. After calculating these risk-adjusted measures, he is deciding which of them provides the best appraisal of his portfolio's performance, considering both return and risk relative to a benchmark.