Are there any differences or maybe even a added performance difference between the 2?

Depends on what your looing for ?
If it's better weight transfer you could just unhook the front swaybar and run drag shocks.
If it's handling your after you actually want stiffer springs then your car already has.

He's right.

In drag racing, it is nearly all about weight transfer, but it road racing or anything else that requires turning, you really want to limit weight transfer mostly. I have heard of mildly modified cars running V6 springs/shocks on the rear and being very happy with that. As for road course handles, OE is just too "average consumer friendly" soft and requires upgrade. Even WS6 cars can be easily improved on, but they are way more stable from the factory than the regular cars.

was mainly looking at ride height and drag racing differences

Guess the drag race part got covered anyway. As for ride height, a V6 car's springs may cause a V8 powered car to ride a bit lower, especially in the front. However, you don't want soft springs in the front of a drag car since stiff front springs help promote rearward weight transfer under acceleration.