I know i was seriously missing ABS last weekend. There's something to be said for all four brakes contributing max braking every time regardless of conditions/tire temps or bad habit.
ABS seems to be the next big step. The big dogs in the vintage class(es?) at the Optima stuff are running retrofits or aftermarket kits.
One of the drives even commented to me in Vegas the first year I got to go that it was the biggest difference between the old cars and new cars, right after a guy blew a corner and slid off the track.