I disagree a bit there. I do agree that the Performance is pretty much maxed out on the SVT, but mods still give you some version of performance.
You can achieve better performance with:
- handling - going with the better suspension.
- shifting - if you get the Short Throw and Dog Bone Mount.
- off the line pick up - Cold Air Intake, Throttle Body
- more horsepower - Off-Road Pipe or High Flow Cat <- most gains here. Avg 6-7hp
- better overall engine flow - Tune
And so in turn, your car has better driveability.
But definitely stock for stock, the SVT is a great product that Ford released. Too bad they didn't release it with a turbo or supercharger. Although the internals of the engine can handle those up to 350hp. So, if major horsepower is what you are going for, may want to look into forced induction.