This paper revisits the R2 metric, a widely used metric in multi-objective optimization. Existing R2 metrics typically utilize discretized utility function distributions and suffer from weak Pareto fit. In this study, we analyze the properties of the R2 metric using a Chebyshev utility function with a continuous uniform distribution. We demonstrate that this continuous variant is Pareto-fitting and present an efficient computational procedure. Specifically, (a) it has a computational complexity of $\mathcal O(N \log N)$ for bivariate problems, and (b) the metric can be incrementally updated without recomputing the entire set when solutions are added or removed. This presents an efficient and promising alternative to existing Pareto-fitting unary performance metrics, such as the hypervolume metric.