I can hit 144 fps in space, and it won't go below 100 elsewhere (though I didn't try RES) in Ultra settings, but I couldn't see much difference in ED. Frame rate only matters if the pixels change during the interval between one frame and the next, which I don't think I'm exceeding in ED unless I fly 10 meters off the surface at full throttle in a Courier looking sideways. However, the difference in power consumption (and thus fan noise) is quite noticeable, and this is why I decided to lock in at 60 hz / 60 fps.Try setting the display to 120Hz and bringing the graphics down to high/custom. You could well push 120fps with that GPU. In Elite, the difference isn't that pronounced, but in other games, especially fast-paced ones, the increase in fluidity is really noticeable.
Now if I ever decide to buy Overwatch for PC, then I'll be enjoying all 144 hz that this monitor supports