Both of my AW11s have been late ones, an '88 and my current '89. The '87-on models have slightly larger brakes that are less prone to warping the rotors, and supposedly have altered rear geometry as well as different rear shocks. I can't verify the geometry claims that I have read about, but I have had no snap oversteer problems whatsoever in either one. First one was stock springs, Illuminas set 2/F, 5/r, BFG R-1s (yes, this was a long time ago). If anything, it pushed.
My current car has Eibach Pro-Kits, Illuminas 2/F, 5/R, Suspension techniques rear bar set stiff,and 14x7 wheels with Victoracers in 195/55-14 on all four and the balance is wonderful - but absolutely no snap oversteer at all. I have to really work to get the tail out much, I wish it were looser.
Most of the snap oversteer comments I have read come from folks with pre-'87 cars, so maybe there is something to the geometry story.
I'm going back to stock springs on mine because I live at the end of a 7-mile long unpaved county road that has heavy washboard and deep potholes, and the front end crashes out at 20 mph. I can slalom around the holes, but to make the car more practical as a DD, the increased travel will help - it was better before I added the Eibachs. But for normal folk who live on pavement, the Eibachs are sweet, but they may increase the front wheel lockup tendency. But I tend to brake way too late and too hard, so the problem could be me.
I've tried using the ST front bar on full soft, and it seems OK, too - doesn't make the car plow particularly. When I put the stock springs back on, I may go back to the ST front bar along with the ST rear bar full stiff. We'll see.
One other problem - not much room under the front spring perches for big tires. 205/50-15 is probably about it, unless you get some 13s made up that will clear the brakes.