If it was a normal 144Hz monitor and you weren't able to put out a constant 144 fps, it would still provide a smoother experience than a standard 60/75Hz monitor. However as the refresh rate is that much higher than the frames being output to it, it would cause issues that you may be able to see.
The joy of this monitor is that it has G-Sync. G-Sync is Nvidia's version of Freesync - what this does is allow the monitor to dynamically alter its refresh rate to match the framerate being output from the GPU - this results in a *much* smoother experience!