Yes! They seriously do move a lot of air. I very seldom ever need to use mine above the lowest setting. Mine is in the bathroom, and when I sit there with the door closed and the fan on, I can feel a breeze blowing in under the door.
They are reversible too. You can open a window at the far end and bring in air from outside and blow it out the window. Or leave it on exhaust and have it draw air from the open window, creating a nice cross breeze.
Good for cooking odors too. Have it blow in, leave the windows closed and have it blow out the stove hood without turning the confounded noisemaker hood fan on.
I would never be without an FF in any RV.