Thanks for your detailed reply
Maybe it is that I am very sensitive to stroboscopics. More than I am to motion blur. (Or to crosstalk.)
I tried 100, 125, 144, 240 Hz in my game with DyAc+ ON. => 240 Hz is way smoother. 144 Hz and below feels like a downgrade compared to my previous 240 Hz monitor.
Besides, I have a LaCie Electron22blueIV CRT monitor running the game at 125 Hz and the CRT feels way better than XL2546K with 125 Hz DyAC+ ON.
I must be more sensitive to stroboscopics than to motion blur because to me, 240 Hz DyAc+ OFF feels better than 144 Hz DyAc+ ON.
Nevertheless, 240 Hz DyAc+ ON is an appreciable improvement compared to 240 Hz DyAc+ OFF. This is more obvious in situations such as fast crosshair movements to cover two opposite sides.
I should add that I used to play (10 years ago) on a CRT at 100 Hz (sometimes 125 Hz), and it was obvious to me that the higher the refresh rate the better the motion quality. There was quite a significant difference between 85 Hz and 100 Hz. The returns were less with 125 Hz, and I sticked to 100 Hz to allow for a higher resolution (1600x1200).
I was using the word 'motion blur' whereas it actually was a matter of stroboscopics (thanks for the link to your article).
My game has both moving-eye and stationary-gaze situations, but what comes into play for me is the motion clarity in moving-eye situations. See
this video where I am checking different sides while being below the bridge (maybe not the best footage to describe my game, though).
In general, when panning the mouse to check different locations/directions in a short amount of time, I experience a sort of 'blurry' image, whereas it is not what you call motion blur. It is I believe the too low refresh rate (stroboscopic effect). And it is true that DyAc+ greatly helps in this panning situation, not regarding the stroboscopic effect, but by removing actual motion blur. But this is not enough, there is still the too small amount of refreshes per second, the stroboscopic effect, which is a very important component for motion quality in this situation.
Example: I did an experiment in my game, I executed a rotation of my character with constant speed (I just have to press a key for that). See
the video (of course, the video is not how I see through my monitor). With DyAc+ ON, if I focus at a particular location (for instance, the
red entrance here) I can see a blurless image whereas with DyAc+ OFF it is blurry.
=> Strobing allows to remove motion blur in that case. But there is still the stroboscopic effect that is in my eyes the main component (and limiting factor) for motion quality.
=> I believe that an increased refresh rate is beneficial not only for blur reduction (in case of a non-strobed display), but also for stroboscopics. And for me, it would mainly be for stroboscopics.
See
this video with comparison between 240 Hz and 360 Hz where stroboscopics is put into evidence. That is what I am most sensitive to and with my 240 Hz monitors I can kinda "see" it while gaming.
And thanks again, your reply allowed me to realize that I can use Nvidia settings "Fast" for "Vertical sync" which I got confused in believing I couldn't use it without G-Sync. With this, the FPS doesn't drop to half its value whenever there is a performance instability and the image quality is improved.
To get better smoothness in fast motions, 360 Hz is thus appealing (and on a side note, I'm definitely interested in that Razer Avalon). Now, I understand that too slow GtG for the new 360 Hz monitors impairs the benefits of non-strobed blur reduction, but does it also as much impair the expected improvement in stroboscopics from 240 to 360 Hz?
And also I should take into account that there would be no ULMB at 360 Hz.
And I am able to run my game at 360+ FPS more than 95% of the time.