Durt, you've put you're finger on the pivotal question: Authenticity or not?
Admittedly this isn't a suprise to me because I've been tracking the evolution of the Coupe for the past ~ 2 years, after Mariaah was totaled.
After having the good fortune to talk with Peter Brock for several hours about his design philosophy, I am convinced that this is a better car than the original Coupe.
Some facts that shed light on my feelings are:
The original plans for the Shelby Daytona Cobra were much like what the Brock Superformance Coupe has incorporated. That is, the original Coupe was supposed to be as long as the SPF Coupe, but AC had already cut the pieces, to the wrong dimensions, when Peter showed up in England to Execute his design. He actually had to "Backward design" the Shelby Coupe to make use of the parts AC mistakenly cut. Needless to say, he and Bob Negstad weren't real happy about that situation, but time and urgency forced them to "make do."
The 18" wheels will give the owner a broader range of choices for rubber, and brakes, that will make the car safer at speed than can be had with the 15" wheels. Personally, I wouldn't want a 200+ MPH car with 175 MPH tires...not that I would ever drive that fast. ;-)
The on-board AC will make the car much more comfortable in the heat, something the original Coupe wasn't, and neither was (is) the original GT40 a "cool driver." This I found out after talking with Bill Murray who drives the GT40 from the Shelby museum in Colorado.
I have to admit that at my age (56) and after having driven the wheels off of my 427 S/C, Mariaah, on the track and in on the street, a little more comfort, and safety, are very desirable for me.
Safety is the next issue. The Coupe has an integrated roll bar with the ability to take a roll cage that, from my perspective, is mandatory should the Brock Coupe EVER be put into a racing situation.
The steps that SPF went through to make their Coupe look as authentic as it does, took about an hour for the SPF CEO to explain to me. It really has a complete design pedigree that even impresses this old engineer.
There's more to say, but I need to take a nap!
All the best,