I agree with Trukin 100%.
My 5.0 @ 36k miles is starting to get difficult to shift the M-82 trans. Other than that, the SCT tuner, off road Xpipe and cat back have been phenomenal. I beat my car like it owes me money though and it has been nothing but smiles. A replacement magnum trans is being considered for reliability and future mods.
With all of that being said, my old 2010 camaro SS was more refined than this mustang will ever be and the resale values are extremely strong. Good luck.