I put a Maxair fan in my last TT, the temp controlled version with the built in hood. Worked good for a couple years till I sold the TT.
My 5er came with a fantastic vent fan with rain sensor on the roof, and a piece of junk upstairs. I swapped the upstairs unit out with a Maxair, temp controlled with the built in hood. Of the two I think the Maxair if quieter, but they are both very quiet on the lower speeds, and both move a lot of air when cranked up.
2015 Ram 3500 Laramie CTD, 4X4, AISIN, B&W Companion Puck Mount
2016 Heartland Bighorn 3270RS, 1kw solar with Trimetric and dual SC2030, 600 watt and 2k inverters.