https://www.digitaltrends.com/computing/freesync-vs-g-sync/ schrieb:
Both FreeSync and G-Sync also start to suffer when the framerate isn’t consistently syncing within the monitor’s refresh range. G-Sync can show problems with flickering at very low framerates, and while the technology usually compensates to fix it, there are exceptions. FreeSync, meanwhile, has stuttering problems if framerate drops below a monitor’s stated minimum refresh rate. Some FreeSync monitors have an extremely narrow adaptive refresh range, and if your video card can’t deliver frames within that range, problems arise.
Most reviewers who’ve compared the two side-by-side seem to prefer the quality of G-Sync, which does not show stutter issues at low framerates, and thus smoother in real-world situations.