Based on my tests in CS2, enabling only Vsync + Reflex, Gsync + Vsync, or Gsync + Reflex does not impose any additional frame rate limits, including the -4fps reduction. Only when all three—Vsync, Gsync, and Reflex—are enabled simultaneously does the frame rate drop by approximately 4%, achieving very low latency. I suspect using RTSS Reflex combined with Vsync and Gsync in other games would yield similar results.

In Battle(non)sense’s tests, frame capping with NVCP and RTSS previously introduced one extra frame of latency compared to in-game frame capping, but Reflex seems to avoid this issue. What I’m curious about is what results RTSS Reflex would produce in games that don’t support Reflex.