Love my Flex-fan, and it is not really that noisy....
it purrs, and does change the tone of the engine, but mine is not loud, just different.... now a bad water pump bearing that is loud.
One thing to mention, if you have an auto tranny go for the 16" fan, the 17" will fit if you bend the cooler lines down a tad, but it is close, I cut mine twice before I bent them....
Now I have a manual tranny and it is not an issue, but if you wanted to get a shroud in there you would have to go 16".