Have you factored complexity/expense of installation?
One system appears to require much more installation commitment than the other.
Regarding "best handling system" the key word is system. What's up front? Will the front suspension handicap the rear?
How much "handling" does your typical usage of the car require?
Installing a single adjustable shock on one system and a triple adjustable on the other will make that system handle better than the other IMO.
Exhaust routing options for each system?
It's a never ending game of factors.
