I have a manual one and so far am happy with it, Less to go wrong than with the automatic ones, but there are advantages to the automatic ones too.
I will make a statement about the Maxx Air here.
Due to the way it works (It blows air DOWN onto the roof) unlike the Fantastic fan it does not need to close if it starts raining, The Maxx Air keeps right on working rain or shine.. This is why if my FF ever goes south, Well, you can figure out the rest of that I'm sure.
That said: I expect teh FF to last at least another decade or two.
As for me (My body that is) well, that's not so sure.. I am one year younger than my mother when she passed on.