I put Maxxair covers on our new to us camper this past spring when we brought it home.
I replaced the bathroom fan/vent with the Vortex replacement unit. It works great with the "pull the pins to remove" cover.
I removed the old vent-only from the bedroom and installed our fantastic fan (removed from our old popup and painted nicely) in the opening. Had to order a shroud to fit the Fantastic fan shape.
It does not open 100% under the cover, but we haven't noticed any issues with slowed or noisy airflow. It is quite nice and has the little screen for bugs in the slotted vents in the cover.
We get soft light through them in the days, not blinding and not dark...just right ;)
Made sure the openings were facing towards the back of the camper. They show no signs of having been barreling at > 80mph and sometimes into the wind :E
Watch for them on free shipping sales or Amazon as they are quite bulky ;)