How would you go about benchmarking a scheduler anyway? Run 10 processes and see which one finishes them fastest?
Depends on what matters most to you: Minimum/Maximum Latency, fastest completion of a specific app, fastest completion of a single app, fastest completion of all apps, CPU overheat, etc.
Lowest latency, obviously, would be a pure priority scheme. FIFO has lowest CPU overhead. Highest total throughput would be Shotest Time First. Multilevel Queue and Round Robin both try to give acceptable throughput and acceptable latency at the cost of CPU overhead. And so on and so forth.
In short, the optimal scheduler for your system is determined by your system requirements. A RTOS is going to use Priority. A general purpose OS is going to use some form of Round Robin or Multilevel Queue. And so on.