I buy a stick whenever I can, and the Mustang has one, but I have to admit, I am impressed with the 10 speed auto in my new Ecoboost F-150. If you are towing a trailer, and set the cruise control, it will just down shift to maintain speed up steep hills! And the reports I hear is that tranny (jointly developed with Chevy) is nearly bullet proof!
As for electric (etc) vehicles, if you add in the manufacturing, disposal, and generating the electric, all (if any) gains to the environment get wiped out. Maybe some day … but for now I think it is just a con game.