True but with all that they have that is better, it doesn't really translate into big number differences. They are still pretty closeDon't forget that the Shelby has a better transmission and cooling for the transmission and rear end that the PP2 doesn't have. It also has lighter and probably better brakes than the PP2. Then there's that Voodoo engine too.
If Ford did the off the shelf parts thing for the Mach1, there would still be a gap between the Mach1 and the GT350.
Add in the fact that you can have a savings of $10 - 20K with a PP2, that can buy you a lot of modifications to help make up that difference. Add in the PP2 is a better daily driver (GT350 is stiffer) and had an engine that doesn't consume a quart of oil every 1,000 miles and is slightly better in city and combined mpg.
True, if you want a track God, GT350/Mach 1 all the way. If you just want a tight handling Mustang with very good performance, the PP2 gives you a great option.