To answer OP"s question: Drive your IX like a FWD, that's how most AWD cars handle anyway.
1. Quatros were superior to IX's.
2. If you throw enough money and technology (that already exists), like torque shifting, as in sending most or all of the power to the front, rear or even side wheels, apples to apples, AWD will kick RWD ass every time. It just costs a huge amount of money to do.
3. F1 is limited by a very tight rules package. If the rules were free, ALL F1 cars would be AWD... but, astronomical budgets of today would seem like pocket change in comparasing... not because of AWD, mostly because of aero, but sophisticated AWD systems would account for a good part of that budget.
Few months ago I threw away about 200 pounds of car magazines, so unfortunately, I can't show you the article, but one of the ten or so year old F1 Racing mags, had asked Frank Williams what kind of car would he build if the rules were free.
Guess what? Among other changes like a flat wedge-shaped body, with closed wheels, he would have a SIX wheeled AWD car.
On the track, in the dry, I would take RWD.
In the wet, AWD is way better.
I agree that, weight makes a big difference in handling. Extra 200-300 lbs of AWD technology doesn't help.