In my opinion, the Superformance is among the most accurate replicas. However, in my research I have noticed a few things . . .
The "mouth" seems a little more oval-shaped than the original. Also, the radius of the curve of the mouth opening (where the body curves "into" the mouth) seems a little tight -- in other words, the mouth opening is a little too sharp.
The panel under the mouth, between the mouth and the
oil cooler intake, looks more concave than on the originals.
The radiator, which of course is visible through the mouth, leans forward (top of rad forward of bottom); it leans rearward on the originals.
The windshield wipers park to the left -- does anyone know whether any originals had wipers that parked on the left? The originals I've seen have wipers that park to the right, but I don't know whether they all did.
The side vents are not exact duplicates of the originals' vents.
The original S/Cs had roll bars that were visible behind the seat, in front of the rear bulkhead -- the bar is exposed where it goes through the body and continues down to the mounting points on the chassis. The SPF roll bar is visible on the inboard side, but not on the outboard side. This is closer to original than most replicas -- as far as I know, only ERAs, and of course Kirkhams and Shelbys (and the former High-Tech?), have roll bars that are exposed inboard and outboard like the originals.
The rear-facing support tube of the roll bar is somewhat more vertical on the SPF than on the original cars, and as a result it goes through the body at a point closer to where the main hoop tubes go through the body. Again, ERA, Kirkham and Shelby are closer to the original design.
That's all I can think of. It sounds like a long list of inaccuracies, but they are all, I think, fairly minor. Overall, I think the SPF is considerably more accurate than the vast majority of the replicas. In my opinion, the only replicas that are closer in appearance to the original Cobras are the Shelby and the Kirkham (tied for best), closely followed by the ERA. The SPF is high on my list of best replicas.