Man I wish I could build stuff that looks like that "Bail Out" Mustang.
Here is what I think Ford has to build to a price and to the widest demographic that is possible. Therefore they compromise more than a custom builder of the restomod would have to. Once you add the full cage the advantage of the modern monocoque frame is greatly reduced if not eliminated altogether. Then with the restomod the suspension is more focused to the intended use rather than being compromised for the broader use desired by sales. Since any engine package is available to the restomod and again can be custom tailored to the restomod intended use It has the advantage. For over all year round use and longevity the new Ford has the the advantage for a singular performance test the restomod.
2010 GTRR in 5.0 Magazine [http://www.mustangandfords.com/featured-vehicles/m5lp-1212-2010-ford-mustang-gt-rr-total-fabrication/viewall.html]
2015 White SC, PP, etc....