I felt it (the one I drove) was slightly (and I say slightly) on the soft side around the corners compared to the a 3xx, but that’s just me. Could have been tires, could have been suspension setup (though both was running stock on both cars i think). The bimmer had aftermarket brakes, but so did the infiniti, so it was pretty much a wash. For me the bimmer just felt better, and no I don’t have a bimmer fetish.In any case, both did better than my audi that has a front overhang issue. Though I love seem folks with rwd only drive in snow and ice. Oh wait, it doesn’t snow in SD.
I agree that the BMW from factory feels a little tighter than the G sedan and the auto G coupe. My feeling was that, tires and suspension can be upgraded easily if I were to track my car more often but it’s much harder to get more power unless you have turbo. Since the G35 is priced like a 325/328, it has about 80HP advantage. The big seller for me was the Brembo on the G35 6MT. Both the G and the 3-series have AWD option w/out the massive overhang the Audi have ;-).
I agree with you about DSG. DSG is an amazing transmission and would make it very easy to get peak performance every time. However, it will never give me the grin I get heel-toeing into corners. It’s definitely a hard choice for me.