GT Q2 Diesel remapped with the rarer wheels - but then I would say that. Having driven a GT without Q2 I honestly can say I would not drive a GT, maybe any Alfa, without it - I note on the new generation it is more standard.
That the GT has been put to bed is a tragedy, it is / was the best looking Alfa, they should have revamped it but kept the shape - the Brera nearly had it, but was let down with the backend of Vanessa Phelps.
The newer generation on Alfas have pretend LSDs, they are managed by electrotrickery rather than a physical differential as in the Q2 GT.
I did test drive a few GTs as i was buying the Q2. A Cloverleaf (minus the Q2) and a Lusso. The Lusso was comfier, the Cloverleaf about the same. But the Q2 was an absolute blast around corners, islands and in fact under acceleration of any sort.
It manages the distribution of power to the driven wheels in such a clear and unmolested way. The 159 I had tried to do this with the electrical combination of brakes and throttle, but ended up just being an pain. The GT seems to manage traction in the most ridiculous of circumstances, "normal" road driving that is.
For example, coming out of an off camber island in the wet/damp, 2nd gear, 3K revs, apply more power, grip. No understeer, no wheel spin, no flashing of the traction control. No fuss, just grip.
I love it!
Added to the LSD the Q2 has lower and stiffer shocks, differently sprung springs and a stiffer arm. Makes for a sorted front wheel drive car.