Pete, real world testing < Internet theory posts.
Pretty easy: off the shelf "coilovers" will always be inferior to properly set up/tuned dampers (with appropriate springs). I believe that's what the Racepace TEINs are (customised for your car).
RE: the Evo, the damper rates and higher spring rates will contribute to the faster track time. Standard Evo Billies are a compromise street setup. MCA red would be more track focused.
A mate changed his Evo's suspension to MCA blue. I've driven before and after (on the street only) and can immediately feel the difference.