I'm nowhere near good enough at the track to find out personally but I will tell you I feel more secure/planted with the RS arms etc... Not like they can't be retro-fitted

 

As in adventure capitalist Bobby G..looks awesome

 

Other criteria set aside, it sounds to me like comparing a downtown penthouse with a house on the beach. As a daily driver, the GT3 does not have enough front ground clearance to be viable in the US. As a track day car, the AM V8 will inevitably leave you wanting more (more juice, more brakes, more body control).
I recommend thinking hard about what you'd like to do with the car.
Compromises always end up being just that.