Sorry to say this but most true blue Mustangers (such as myslef) think the 2010 Mustang is the beginning of the end for its styling design. Most of the stangers agree that when seen "live" the backend of the car is a total f*ck-up in design as its bulging rounded deck lid lines makes the car look like a sedan. And the angling up of the lights is a complete screwup as no Mustang in its history ever had such an angling up which looks totally dumb.
The car is a pig in weight as well as it damn near weights 500 more pounds than the 370Z. And for a 4.6L engine the car barely makes 315 BHP.
Also the stock suspension is not on the same level as the Z when it comes slalom types of events as the Mustang is predominently set up for straight line. I am not saying that it cannot hold teh rode...I am just saying that to do course-running with guaranteed absolute precision and ease of hnadling the suspension needs to be upgraded to exactly what the Shelby-GT (not the Shelby GT500) has.
When I describe to my fellow club stangers why I left the pack I say it this way:
Mustang = RAW............Z = Refined.
My vote:
Mustang =
..............Z =
And this is coming from me, a guy who has had nothing but Mustangs for the 38 years I have been driving.