It depends on your priorities -- are you more sensitive to stutters/tearing or more sensitive to motion blur? Most 240Hz monitors will do reasonably good blur reduction at a lower refresh rate (120Hz).
One biggie is that the AOC 240Hz display has no blur-reduction strobe backlight mode.
They do make a big difference in blur-reduction, if you like super-sharp motion clarity (like on a CRT). LightBoost was the original, and manufacturers followed suit with things like "Motion Blur Reduction Mode" or "ULMB" (Ultra Low Motion Blur) or "Dynamic Accuracy" (dyAc - BENQ).
FWIW, there is less motion blur during strobed 120Hz than non-strobed 240Hz, if your eyes are more fussy about motion blur than with input lag/tearing/stutters.
If you like eliminating tearing & stutters, then definitely GSYNC/FreeSync is the way to go (see TestUFO simulation of G-SYNC
showing smooth stutterfree transition during framerate changes, made possible by G-SYNC/FreeSync). Though it's often nice to have a choice to be able to enable a blur reduction mode for the certain games that benefit from it.