It will try and sync to a scanline rather than a time interval, and as such can reduce microstutter, which is important when using enhanced sync. Enhanced sync already has microstutter issues, and using a normal 30FPS RTSS cap will just make it worse. x/2 s-sync should make the microstutter more tolerable. It's much lower, at least compared to vsync without any FPS cap. 60FPS uncapped vsync can have 100ms or more of total latency. With s-sync and enhanced sync, you should be getting 60ms or less of total latency. However, you should be able to achieve the same input lag reduction using normal vsync with a "Hz - 0.01" cap. But I haven't tested. But s-sync + enhanced sync has better latency consistency. The -0.01 cap with vsync has the issue of latency oscillation, because the 0.01 cap will result in each frame being synced a bit later every time, so the sync position crawls across the screen from top to bottom, and so latency varies by 16.7ms over time. With s-sync + enhanced sync, this is improved and the latency does not vary as much, depending on how well RTSS can sync to the target scanline. Anyway, that's a bit too much detail to worry about, really. You should simply prefer what feels and looks best to you. If normal vsync with a -0.01 cap feels better to you, use that. If s-sync with enhanced sync looks better, use that.