I've owned my 2011, 5.0, 6 speed (Chinese slush box), 3.73, brembo package for over a year now.
Mods to date........lowered Ford K Racing springs, adj panhard bar, Flowmaster cat-back, Airaid CAI, American Muscle 93 octane 'tune'
To date I have had zero issues with my tranny, I've got less than 3000 miles on it, it is stricktly for pleasure. No engine tick issues and no #8 cyl issues either. You can see out of it, unlike the Camaro and it doesn't feel like a tank like the Challenger.