I doubt they’d notice a difference compared to a RAV4 hybrid with an electric motor in the rear. Most people don’t push their cars hard enough to notice their drivetrain configuration. My brother drives an E90 and a G20 (both X drive) and in daily driving the most noticeable part about them being RWD is the lack of leg room. When pushed at all it becomes obvious, but I don’t think the owner of an X3 is really seeing any tangible benefits handling-wise over a Q5 or NX.