androbourne :
Yes I get that. What I'm saying is "primarily useful at 30-60fps". Totally do not agree with that statement at all.
There has been many benchmarks that show that isn't some set small range and it just "works best" within those ranges. That's not how Gsync or Freesync works.
Every monitor, card and system setup will have different ranges and settings for which those feature work best at.
I'm not saying your other statements are wrong. Just dont agree with that exact statement.
Anyways, take it for what you will. Moving on.
I think you are misreading it ... the sync utility is working any different. The impact of what the user sees is different. The problem that G-Sync and Freesync are designed to correct is most seen at low fps. G-Sync and Freesync have a lot of work to do here and the observation with or w/o G-Sync / Freesync is very pronounced.
When you get past 60 fps ... the problem without G-Sync and Freesync is not as pronounced. Therefore the level of improvement which G-Sync and Freesync can provide must be less. It's not that the quality provided is any less...
it's that the baseline is less allowing for greater levels of perceived improvement.
Quality of image at 40 fps = 55 w/o G-Sync and Freesync
Quality of image at 40 fps = 85 w/ G-Sync and Freesync ... improvement = 30
Quality of image at 50 fps = 65 w/o G-Sync and Freesync
Quality of image at 50 fps = 90 w/ G-Sync and Freesync ... improvement = 25
Quality of image at 60 fps = 75 w/o G-Sync and Freesync
Quality of image at 60 fps = 95 w/ G-Sync and Freesync ... improvement = 20
Quality of image at 70 fps = 85 w/o G-Sync and Freesync
Quality of image at 70 fps = 97 w/ G-Sync and Freesync ... improvement = 12
Quality of image at 80 fps = 90 w/o G-Sync and Freesync
Quality of image at 80 fps = 98 w/ G-Sync and Freesync ... improvement = 8
Quality of image at 80 fps = 100 w/ ULMB ... improvement = 10
Again, this is not my conclusion ... read any technical article in the subject and they all say the same thing (from link above)
....around 40 - 75fps typically delivers the best results compared with Vsync on/off. At consistently higher frame rates as you get nearer to 144 fps the benefits of FreeSync (and G-sync) are not as great, but still apparent.
Of course you are welcome to disagree but that is the widely accepted consensus ... which is why people turn off G-Sync and use ULMB
https://hardforum.com/threads/gsync-vs-ulmb-for-gaming.1841352/
ULMB has the biggest wow factor for me. Even with a ROG Swift, 144Hz GSYNC still blurs. But turn on ULMB and all of a sudden the backgrounds come in sharp focus
Even 90 fps or above ULMB is probably better. G-Sync is greatest especially when you're only getting 60 fps or less. Between 60 and 90 fps is where you must make a choice between G-Sync and ULMB. I suppose this depends on the game. But the dream condition is to always be above 90 fps, where ULMB would be better.