Having run both the "Centerline style" set up, and the "Alfaholics style" set up I will chime in with my $.02 worth...
I will echo two things from previous posts that I think are most important to consider. First, how do YOU want your car to handle? And, what are your expectations for both where u will drive, and what you want your car to be capable of.
When I was running the Centerline type set up, I was very happy with with it, and I will concur with the description used by others here, that it was like a go kart. However, by that I mean it was very stiff, and the suspension did not move much, so the majority of the handling feel was a result of tire grip, and much less from suspension compliance. On a smooth road, with grippy tires, it felt great, and cornered very flat. However, even slightly rough roads were rattle going slow, and upset the car going faster. Since the factory suspension had much more lean in cornering, the stiffer suspension with flatter cornering just seemed faster, especially when paired with modern grippy tires.
I read an article later about different approaches in suspension between North American tuners, and those in Europe that got me interested, and I sourced and installed the fast road kit from Alfaholics, along with koni fellows all around, as well as their recommendations for bushings, and removal of the rear sway bar, (however, I waited to remove the rear bar until I installed everything else, and tried it out with ). The most noticeable difference was how much more lean there was dialed back into cornering. However, not nearly as much as factory, and in spite of the lean, it felt grippy, but more tossable. it felt smooth, but when the rear sway bar was removed, it seemed even more smooth, and definitely improved feeling here when transitioning corners. Further, this set up was simply more compliant, letting the suspension "work" more, and therefore even lowered about an inch the same as with the Centerline set up, bottomed out less and was less harsh over rough roads.
Being lowered, both setups were challenged over speed bumps.
I don't race, and haven't autocrossed in years, so I have no idea which setup was numbers quicker, but they both felt better and faster to me than factory, but just in different ways.
Currently: 1966 Giulia Super Previously: 1971 series ll 1750 GTV, '73 Spider Veloce, '69 Berlina, '69 GTV, '74 Spider Veloce