We picked up the trailer from the dealer today with the new MaxxFan installed. I posted some pics under "Garfield" in members photos...
The fan has the same features as the Fantastic Fan (3-speed, thermostat, reverse, and a manual control for opening/closing the vent) except for no rain sensor or vent closing/opening motor which is not needed because of the protective cover. The cover is open/shut manually by turning a knob. Once open/closed the vent can be locked by pushing on the same knob. When closing the vent the fan shuts off automatically.
I find the manual operation of the MaxxFan much more intuitive -- I was always trying to open/close the Fantastic Fan manually and ended up fighting the motor even though it was disengaged. Maybe I should have read the FF manual more carefully -- but you know what they say about us guys being too proud to read the instructions!
The MaxxAir's cover really does keep the rain out -- on the way home from the dealer the vent was open and I drove through a torrential downpour but not one drop of rain got inside the trailer. To prevent mustyness I plan on leaving the vent open all summer long and only close it over the winter.
The MaxxFan's fan, although mounted flush with the ceiling is a little quieter than the FF which will be nice for sleeping. The only downside of the MaxxFan is that it dosen't seem to push air with the same force as the FF -- likely due to the cover restricting air flow.
Still, I'm very pleased with the MaxxFan and will likely replace the FF in the front of the trailer in the Fall during the next service.