GT Suspension

Those statements are all just an opinion
Not all. The lighter can definitely be proven and proper geometry, depending on the purpose of the car can also be quantified.

That said, there's tons of different suspension theories and ways to go about it. What works me may not work for the next guy. Honestly If I'd have the money, I'd built 2 identical cars, one torsion, one with this kit, get some true numbers for comparison