That's why Steeda called it the G-Track suspension kit. My customer's Roush #13 has it and corners are go kart quick, but you have to be careful at the edges of it's regime because it will step outside on ya'. . . . LOL.
Sticky tires will have more effect than anything else you can do. New good summer tires will perform far better than worn all seasons. But warmed-up race tires will trump street tires regardless of suspension design.
And what newer cars are you talking about? It's not like your 2003 Mustang GT was a world-beater when it was brand new... It's better than most, worse than some. That part hasn't changed.