I have owned every version of the Crossie. SRT coupe, Convertible, Limited coupe and convertible. Manual shift and AUTO
I'll Put it simple
Off the line acceleration, SRT is your best choice.
However, I never, I repeat, I Never lost a challenge at the Dragon against an SRT
However, I did lose to another Manual Limited.
One time. To a much better driver.

Manual tranny gives you much more control of the power application both acceleration and braking, through the drive train. Less braking, front wheels spinning free, better control in the twisties.
I depends on what and how you like to drive.

Both versions exceed 160 MPH in a land where over 70 MPH gets you a citation. Neither exceeds 70 MPH for more than a nano second in traversing the Dragon.

Currently I have an SRT coupe with the auto. And a Limited convertible with the 6 speed. It is the 6 speed I prefer to drive, especially at the weekend gatherings.