But there are also 3.7 without 'rev hang'.
I have a very early 3.7 from 2012 and up to now never ever I had 'rev hang'.
As we have motorways without speed limit in Germany, I could even drive my 3.7 up to topspeed, no 'rev hang' at all.
By the way on this motorways and higher speed, the 6th gear is very comfortable on long-distance runs.