I'm not saying there aren't any well done FFR Coupes. If you compare the quality of the kit and the use of donor Mustang parts to a Superformance, I take the Superformance.
The fact that Shelby autographed an FFR does not mean he endorses the FFR. Remember Shelby v. Factory Five Racing?
Remember Shelby having the first Brock Coupe impounded by customs?
Shelby has offically licensed the SPF Coupe.
P.S.: Shelby will sign anything. (For a fee.)
At least he didn't find any more "original" Cobras in his Goodyear Racing Tire warehouse!
In general, SPFs are worth more than FFRs. Check the for sale ads.