Not sure about the Spitfire but I can still out turn 109s except for maybe the G-2 (but I wonder if that is still a bit overdone). The handling is definitely more difficult and the stability difference between the E and M is more pronounced but I think this is "more right" in terms of the realism of the P-40.
It's still a wonderful fighter with a troubled reputation but in the right hands its easily competitive at low and medium altitudes.
I'm looking forward to having a new 3D model and some new variants... especially if we get a P-40N. A few hundred pounds lighter and with more engine power. That could be fun